Refereed Journal Articles

Huanyu Li, Olaf Hartig, Rickard Armiento, Patrick Lambrix: Ontology-Based GraphQL Server Generation for Data Access and Data Integration. In Semantic Web Journal 15(5), pages 1639-1675. 2024
download camera-ready version DOI 10.3233/SW-233550 Github repo of OBG-gen, including the material of the evaluation
Patrick Lambrix, Rickard Armiento, Huanyu Li, Olaf Hartig, Mina Abd Nikooie Pour, and Ying Li: The Materials Design Ontology. In Semantic Web Journal 15(2), pages 481-515. 2024
download camera-ready version DOI 10.3233/SW-233340 current version of the ontology Github repo of the ontology
Ora Lassila, Michael Schmidt, Olaf Hartig, Brad Bebee, Dave Bechberger, Willem Broekema, Ankesh Khandelwal, Kelvin Lawrence, Carlos Manuel Lopez Enriquez, Ronak Sharda, and Bryan Thompson: The OneGraph Vision: Challenges of Breaking the Graph Model Lock-In. In Semantic Web Journal 14(1), pages 125-134. 2023
download camera-ready version DOI 10.3233/SW-223273
Sherif Sakr, Angela Bonifati, Hannes Voigt, Alexandru Iosup, Khaled Ammar, Renzo Angles, Walid Aref, Marcelo Arenas, Maciej Besta, Peter A. Boncz, Khuzaima Daudjee, Emanuele Della Valle, Stefania Dumbrava, Olaf Hartig, Bernhard Haslhofer, Tim Hegeman, Jan Hidders, Katja Hose, Adriana Iamnitchi, Vasiliki Kalavri, Hugo Kapp, Wim Martens, M. Tamer Özsu, Eric Peukert, Stefan Plantikow, Mohamed Ragab, Matei R. Ripeanu, Semih Salihoglu, Christian Schulz, Petra Selmer, Juan F. Sequeda, and Joshua Shinavier: The Future Is Big Graphs: A Community View on Graph Processing Systems. In Communications of the ACM 64(9), pages 62-71. Sep. 2021
download camera-ready version DOI 10.1145/3434642
Sijin Cheng and Olaf Hartig: OPT+: A Monotonic Alternative to OPTIONAL in SPARQL. In Journal of Web Engineering 18(1-3), pages 169-206. 2019
download camera-ready version DOI 10.13052/jwe1540-9589.18135
Olaf Hartig and Giuseppe Pirro: SPARQL with Property Paths on the Web. In Semantic Web Journal 8(6), pages 773-795. 2017
download camera-ready version DOI 10.3233/SW-160237
Olaf Hartig and Jorge Pérez: LDQL: A Query Language for the Web of Linked Data. In Journal of Web Semantics 41, pages 9-29. Dec. 2016
download camera-ready version DOI 10.1016/j.websem.2016.10.001
Ruben Verborgh, Miel Vander Sande, Olaf Hartig, Joachim Van Herwegen, Laurens De Vocht, Ben De Meester, Gerald Haesendonck, and Pieter Colpaert: Triple Pattern Fragments: a Low-cost Knowledge Graph Interface for the Web. In Journal of Web Semantics 37-38, pages 184-206. Mar. 2016
download camera-ready version DOI 10.1016/j.websem.2016.03.003
Olaf Hartig: An Overview on Execution Strategies for Linked Data Queries. In Datenbankspektrum 13(2). Jul. 2013
download camera-ready version DOI 10.1007/s13222-013-0122-1
Olaf Hartig and Andreas Langegger: A Database Perspective on Consuming Linked Data on the Web. In Datenbankspektrum 10(2). Oct. 2010
download camera-ready version DOI 10.1007/s13222-010-0021-7

Books

Olaf Hartig: Querying a Web of Linked Data: Foundations and Query Execution. Volume 24 of Studies on the Semantic Web, 248 pages, ISBN: 978-1-61499-630-9 (IOS Press, print), 978-1-61499-631-6 (IOS Press, online), 978-3-89838-713-2 (AKA)

Patents

Bradley R. Bebee, Bryan B. Thompson, Thomas James Lewis; and Olaf Hartig: Acceleration Techniques for Graph Analysis Programs. U.S. Patent 11900079, February 13, 2024
download entry in the Google Patents database
Bradley R. Bebee, Bryan B. Thompson, Thomas James Lewis; and Olaf Hartig: Acceleration Techniques for Graph Analysis Programs. U.S. Patent 11200032, December 14, 2021
download entry in the Google Patents database
Bradley R. Bebee, Bryan B. Thompson, Thomas James Lewis; and Olaf Hartig: Acceleration Techniques for Graph Analysis Programs. U.S. Patent 10409560, September 10, 2019
download entry in the Google Patents database

Refereed Conference Papers

Shahrzad Khayatbashi, Olaf Hartig, and Amin Jalali: Transforming Event Knowledge Graph to Object-Centric Event Logs: A Comparative Study for Multi-dimensional Process Analysis. In Proceedings of the 42nd International Conference on Conceptual Modeling (ER), Nov. 2023
download camera-ready version Github repo with the implementation of the transformation Github repo with supporting material and instructions for reproducing the evaluation
Sijin Cheng, Sebastian Ferrada, and Olaf Hartig: Considering Vocabulary Mappings in Query Plans for Federations of RDF Data Sources. In Proceedings of the 29th International Conference on Cooperative Information Systems (CoopIS), Nov. 2023 (Best Paper Award winner)
download camera-ready version Github repo with the experiment code
Minh-Hoang Dang, Julien Aimonier-Davat, Pascal Molli, Olaf Hartig, Hala Skaf-Molli, and Yotlan Le Crom: FedShop: A Benchmark for Testing the Scalability of SPARQL Federation Engines. In Proceedings of the 22nd International Semantic Web Conference (ISWC), Nov. 2023
download camera-ready version Github repo for FedShop FedShop200 datasets and queries on Zenodo
Sijin Cheng and Olaf Hartig: LinGBM: A Performance Benchmark for Approaches to Build GraphQL Servers. In Proceedings of the 23rd International Conference on Web Information Systems Engineering (WISE), Nov. 2022
download camera-ready version extended version on arXiv (abs/2208.04784) Github repo for LinGBM Github repo with the experiment code
Robin Keskisärkkä, Eva Blomqvist, and Olaf Hartig: Optimizing RDF Stream Processing for Uncertainty Management. In Proceedings of the 16th SEMANTiCS Conference, Amsterdam, The Netherlands, Sep. 2021 (Best Paper Award winner)
download camera-ready version Github repo with the experiment code
Sijin Cheng and Olaf Hartig: FedQPL: A Language for Logical Query Plans over Heterogeneous Federations of RDF Data Sources. In Proceedings of the 22nd International Conference on Information Integration and Web-based Applications & Services (iiWAS), Dec. 2020 (Best Paper Award winner)
download extended camera-ready version same extended version on arXiv (abs/2010.01190)
Robin Keskisärkkä, Eva Blomqvist, Leili Lind, and Olaf Hartig: Capturing and Querying Uncertainty in RDF Stream Processing. In Proceedings of the 22nd International Conference on Knowledge Engineering and Knowledge Management (EKAW), Sep. 2020
download camera-ready version Github repo with the experiment code
Robin Keskisärkkä, Eva Blomqvist, Leili Lind, and Olaf Hartig: RSP-QL*: Enabling Statement-Level Annotations in RDF Streams. In Proceedings of the 15th SEMANTiCS Conference, Karlsruhe, Germany, Sep. 2019 (Best Paper Award winner)
download camera-ready version Github repo with the experiment code
Muhammad Saleem, Alexander Potocki, Tommaso Soru, Olaf Hartig, and Axel-Cyrille Ngonga Ngomo: CostFed: Cost-Based Query Optimization for SPARQL Endpoint Federation. In Proceedings of the 14th International Conference on Semantic Systems (SEMANTICS), Vienna, Austria, Sep. 2018 (Best Paper Award winner)
Olaf Hartig, Ian Letter, and Jorge Pérez: A Model of Distributed Query Computation in Client-Server Scenarios on the Semantic Web. In Proceedings of the 27th International Joint Conference on Artificial Intelligence (IJCAI), Stockholm, Sweden, Jul. 2018
Olaf Hartig and Jorge Pérez: Semantics and Complexity of GraphQL. In Proceedings of The Web Conference 2018 (27th International World Wide Web Conference), Lyon, France, Apr. 2018 (Acceptance Rate: 14.8%) blog post about the paper
Olaf Hartig, Ian Letter, and Jorge Pérez: A Formal Framework for Comparing Linked Data Fragments. In Proceedings of the 16th International Semantic Web Conference (ISWC), Vienna, Austria, Oct. 2017 (Best Paper Award winner) blog post about the paper
Olaf Hartig and Carlos Buil-Aranda: Bindings-Restricted Triple Pattern Fragments. Proceedings of the 15th International Conference on Ontologies, Databases, and Applications of Semantics (ODBASE), Rhodes, Greece, Oct. 2016 Web page for the paper
Magnus Knuth, Olaf Hartig, and Harald Sack: Scheduling Refresh Queries for Keeping Results from a SPARQL Endpoint Up-to-Date. Proceedings of the 15th International Conference on Ontologies, Databases, and Applications of Semantics (ODBASE), Rhodes, Greece, Oct. 2016 ... Extended Version in CoRR (abs/1608.08130) Web page for the paper
Olaf Hartig and M. Tamer Özsu: Walking without a Map: Ranking-Based Traversal for Querying Linked Data. In Proceedings of the 15th International Semantic Web Conference (ISWC), Kobe, Japan, Oct. 2016 ... Extended Version in CoRR (abs/1607.01046) Web page for the paper
Olaf Hartig and Jorge Pérez: LDQL: A Query Language for the Web of Linked Data. In Proceedings of the 14th International Semantic Web Conference (ISWC), Bethlehem, PA, USA, Oct. 2015 ... Extended Version in CoRR (abs/1507.04614)
Olaf Hartig and Giuseppe Pirro: A Context-Based Semantics for SPARQL Property Paths over the Web. In Proceedings of the 12th Extended Semantic Web Conference (ESWC), Portoroz, Slovenia, Jun. 2015 (Best Paper Award winner) ... Extended Version in CoRR (abs/1503.04831)
Gunes Aluc, M. Tamer Özsu, Khuzaima Daudjee, and Olaf Hartig: Executing Queries over Schemaless RDF Databases. In Proceedings of the 31st International Conference on Data Engineering (ICDE), Seoul, Korea, Apr. 2015
Gunes Aluc, Olaf Hartig, M. Tamer Özsu, and Khuzaima Daudjee: Diversified Stress Testing of RDF Data Management Systems. In Proceedings of the 13th International Semantic Web Conference (ISWC), Riva del Garda, Trento, Italy, Oct. 2014 Web page for the paper
Ruben Verborgh, Olaf Hartig, Ben De Meester, Gerald Haesendonck, Laurens De Vocht, Miel Vander Sande, Richard Cyganiak, Pieter Colpaert, Erik Mannens, and Rik Van de Walle: Querying Datasets on the Web with High Availability. In Proceedings of the 13th International Semantic Web Conference (ISWC), Riva del Garda, Trento, Italy, Oct. 2014
Olaf Hartig and M. Tamer Özsu: Reachable Subwebs for Traversal-Based Query Execution. In Proceedings of the 23rd International World Wide Web Conference (WWW), Seoul, Korea, Apr. 2014 (Acceptance Rate Web Science Track: 25%) ... Extended Version in the University of Waterloo Technical Report CS-2014-02 Web page for the paper
Olaf Hartig and Johann-Christoph Freytag: Foundations of Traversal Based Query Execution over Linked Data. In Proceedings of the 23rd ACM Conference on Hypertext and Social Media (HT), Semantic Data Track, Milwaukee, WI, USA, Jun. 2012 (Acceptance Rate: 27%) ... Extended Version in CoRR (abs/1108.6328)
Olaf Hartig: SPARQL for a Web of Linked Data: Semantics and Computability. In Proceedings of the 9th Extended Semantic Web Conference (ESWC), Heraklion, Greece, May 2012 (Acceptance Rate: 25%) ... Extended Version in CoRR (abs/1203.1569)
Olaf Hartig: Zero-Knowledge Query Planning for an Iterator Implementation of Link Traversal Based Query Execution. In Proceedings of the 8th Extended Semantic Web Conference (ESWC), Heraklion, Greece, Jun. 2011 (Acceptance Rate: 23%)
Olaf Hartig, Christian Bizer, and Johann-Christoph Freytag: Executing SPARQL Queries over the Web of Linked Data. In Proceedings of the 8th International Semantic Web Conference (ISWC), Washington, DC, USA, Oct. 2009 (SWSA 10-Year Award winner in ISWC 2019) (Acceptance Rate: 17%)
Olaf Hartig: Querying Trust in RDF Data with tSPARQL. In Proceedings of the 6th European Semantic Web Conference (ESWC), Heraklion, Greece, Jun. 2009 (Best Paper Award winner) (Acceptance Rate: 18%)
Olaf Hartig and Ralf Heese: The SPARQL Query Graph Model for Query Optimization. In Proceedings of the 4th European Semantic Web Conference (ESWC), Innsbruck, Austria, Jun. 2007 (Acceptance Rate: 17%)

Book Chapters

Carsten Giebe and Olaf Hartig: Quo Vadis - Social Media. Eine Analyse der Nutzung von Social Media am Beispiel von Facebook bei den Sparkassen in Deutschland. In Holistische Social-Media-Strategien, Springer 2023
Olaf Hartig, Katja Hose, and Juan Sequeda: Linked Data Management. In Encyclopedia of Big Data Technologies, Springer 2019
Maribel Acosta, Olaf Hartig, and Juan Sequeda: Federated RDF Query Processing. In Encyclopedia of Big Data Technologies, Springer 2019
Olaf Hartig: Linked Data Query Processing based on Link Traversal, Chapter 8. In Linked Data Management, CRC Press 2014
Gunnar Aastrand Grimnes, Olaf Hartig, Malte Kiesel, and Marcus Liwicki: Linked Open Data, Semantic Web Datensätze, Kapitel 7. In Semantische Technologien, Grundlagen - Konzepte - Anwendungen, Springer 2011

Dissertation

Olaf Hartig: Querying a Web of Linked Data: Foundations and Query Execution. Dissertation, Humboldt-Universität zu Berlin, Germany, 2014
(Honored with the 2015 SWSA Distinguished Dissertation Award)

Refereed Workshop Papers

Shahrzad Khayatbashi, Olaf Hartig, and Amin Jalali: Transforming Object-Centric Event Logs to Temporal Event Knowledge Graphs. In Proceedings of the 2nd International Workshop on Object-Centric Processes from A to Z (OBJECTS), Sep. 2024
download camera-ready version extended version on arXiv (abs/2406.07596) Github repo with the implementation of the transformation, supporting material and instructions for reproducing the experiment
Gertjan De Mulder, Ben De Meester, Olaf Hartig, Els de Vleeschauwer, and Pieter Colpaert: The Open Circularity Platform: a Decentralized Data Sharing Platform for Circular Value Networks. In Proceedings of the 2nd International Workshop on Knowledge Graphs for Sustainability (KG4S), Hersonissos, Greece, May. 2024
download camera-ready version
Sijin Cheng and Olaf Hartig: A Cost Model to Optimize Queries over Heterogeneous Federations of RDF Data Sources. In Proceedings of the 1st International Workshop on Data Management for Knowledge Graphs (DMKG), Hersonissos, Greece, May 2023
download camera-ready version Github repo with the experiment code
Sijin Cheng and Olaf Hartig: Source Selection for SPARQL Endpoints: Fit for Heterogeneous Federations of RDF Data Sources?. In Proceedings of the 6th Workshop on Storing, Querying and Benchmarking Knowledge Graphs (QuWeDa), online, October 2022
Shahrzad Khayatbashi, Sebastian Ferrada, and Olaf Hartig: Converting Property Graphs to RDF: A Preliminary Study of the Practical Impact of Different Mappings. In Proceedings of the Joint Workshop on Graph Data Management Experiences & Systems (GRADES) and Network Data Analytics (NDA) (GRADES-NDA'22), Philadelphia, PA, USA, June 2022 Github repo for the paper
Olaf Hartig: Foundations to Query Labeled Property Graphs using SPARQL*. In Proceedings of the 1st International Workshop on Approaches for Making Data Interoperable (AMAR), Karlsruhe, Germany, September 2019
Olaf Hartig and Jan Hidders: Defining Schemas for Property Graphs by using the GraphQL Schema Definition Language. In Proceedings of the 2nd Joint International Workshop on Graph Data Management Experiences & Systems (GRADES) and Network Data Analytics (NDA) (GRADES-NDA'19), Amsterdam, Netherlands, June 2019
Yun Wan Kim, Mariano P. Consens, and Olaf Hartig: An Empirical Analysis of GraphQL API Schemas in Open Code Repositories and Package Registries. In Proceedings of the 13th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW), Asuncion, Paraguay, June 2019
Olaf Hartig: Foundations of RDF* and SPARQL* - An Alternative Approach to Statement-Level Metadata in RDF. In Proceedings of the 11th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW), Montevideo, Uruguay, June 2017
Olaf Hartig and Jorge Pérez: An Initial Analysis of Facebook's GraphQL Language. In Proceedings of the 11th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW), Montevideo, Uruguay, June 2017
Olaf Hartig: LDQL: A Language for Linked Data Queries. In Proceedings of the 9th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW), Lima, Peru, May 2015
Jun Zhao and Olaf Hartig: Towards Interoperable Provenance Publication on the Linked Data Web. In Proceedings of the 5th Linked Data on the Web (LDOW) Workshop at the World Wide Web Conference (WWW), Lyon, France, Apr 2012
Olaf Hartig: How Caching Improves Efficiency and Result Completeness for Querying Linked Data. In Proceedings of the 4th Linked Data on the Web (LDOW) Workshop at the World Wide Web Conference (WWW), Hyderabad, India, Mar. 2011 Web page for the paper
Olaf Hartig and Frank Huber: A Main Memory Index Structure to Query Linked Data. In Proceedings of the 4th Linked Data on the Web (LDOW) Workshop at the World Wide Web Conference (WWW), Hyderabad, India, Mar. 2011 Web page for the paper
Olaf Hartig and Jun Zhao: Publishing and Consuming Provenance Metadata on the Web of Linked Data. In Proceedings of the 3rd International Provenance and Annotation Workshop (IPAW), Troy, New York, USA, Jun. 2010
Olaf Hartig: Towards a Data-Centric Notion of Trust in the Semantic Web (A Position Statement). Proceedings of the 2nd Workshop on Trust and Privacy on the Social and Semantic Web (SPOT) at the 7th Extended Semantic Web Conference (ESWC), Heraklion, Greece, May 2010
Olaf Hartig and Jun Zhao: Using Web Data Provenance for Quality Assessment. In Proceedings of the 1st Int. Workshop on the Role of Semantic Web in Provenance Management (SWPM) at the International Semantic Web Conference (ISWC), Washington, DC, USA, Oct. 2009
Olaf Hartig, Hannes Mühleisen, and Johann-Christoph Freytag: Linked Data for Building a Map of Researchers (Scripting Challenge Submission). In Proceedings of the 5th Workshop on Scripting for the Semantic Web (SFSW) at the European Semantic Web Conference (ESWC), Heraklion, Greece, Jun. 2009
Olaf Hartig: Provenance Information in the Web of Data. In Proceedings of the 2nd Linked Data on the Web (LDOW) Workshop at the World Wide Web Conference (WWW), Madrid, Spain, Apr. 2009
Olaf Hartig, Martin Kost, and Johann-Christoph Freytag: Automatic Component Selection with Semantic Technologies. Proceedings of the 4th International Workshop on Semantic Web Enabled Software Engineering (SWESE) at the 7th International Semantic Web Conference (ISWC), Karlsruhe, Germany, Oct. 2008
Olaf Hartig: Trustworthiness of Data on the Web. In Proceedings of the STI Berlin & CSW PhD Workshop, Berlin, Germany, Sep. 2008

Reports, Demos, Posters, etc.

Olaf Hartig, Gregory Todd Williams, Michael Schmidt, Ora Lassila, Carlos Manuel Lopez Enriquez, and Bryan Thompson: Datatypes for Lists and Maps in RDF Literals. In Proceedings of the Poster Session at the 21st Extended Semantic Web Conference (ESWC), Hersonissos, Greece, May. 2024 (Best Poster Award winner)
download camera-ready version SPARQL-CDTs spec Github repo with spec drafts and test suites
Huanyu Li, Olaf Hartig, Rickard Armiento, and Patrick Lambrix: OBG-gen: Ontology-Based GraphQL Server Generation for Data Integration. Proceedings of the Posters, Demos and Industry Tracks of the 21st International Semantic Web Conference (ISWC), Athens, Greece, Nov. 2023
Sijin Cheng and Olaf Hartig: Towards Query Processing over Heterogeneous Federations of RDF Data Sources. Proceedings of the Poster Session at the 19th Extended Semantic Web Conference (ESWC), Heraklion, Greece, Jun. 2022
Olaf Hartig and Pierre-Antoine Champin and Gregg Kellogg and Andy Seaborne (eds.): RDF-star and SPARQL-star. W3C Community Group Report, Dec. 2021. Online at https://www.w3.org/2021/12/rdf-star.html
Olaf Hartig, Maria-Esther Vidal, and Johann-Christoph Freytag (eds.): Federated Semantic Data Management (Dagstuhl Seminar 17262). In Dagstuhl Reports, 7(6) 2017
Olaf Hartig: RDF* and SPARQL*: An Alternative Approach to Annotate Statements in RDF. Proceedings of the Poster Session at the 16th International Semantic Web Conference (ISWC), Vienna, Austria, Oct. 2017 (People's Choice Best Poster Award winner)
Alexander Potocki, Muhammad Saleem, Tommaso Soru, Olaf Hartig, and Axel-Cyrille Ngonga Ngomo: Federated SPARQL Query Processing Via CostFed. Proceedings of the Demo Session at the 16th International Semantic Web Conference (ISWC), Vienna, Austria, Oct. 2017
Olaf Hartig and Olivier Curé: Semantic Data Management in Practice (Tutorial Description). Proceedings of the 26th International World Wide Web Conference (WWW), Perth, Australia, Apr. 2017
Olaf Hartig and Carlos Buil-Aranda: Reducing the Network Load of Triple Pattern Fragments by Supporting Bind Joins. Proceedings of the Poster Session at the 15th International Semantic Web Conference (ISWC), Kobe, Japan, Oct. 2016 (People's Choice Best Poster Award winner) Web page for the paper
Olaf Hartig: Reconciliation of RDF* and Property Graphs. In CoRR abs/1409.3288, Sep. 2014
Ruben Verborgh, Olaf Hartig, Ben De Meester, Gerald Haesendonck, Laurens De Vocht, Miel Vander Sande, Richard Cyganiak, Pieter Colpaert, Erik Mannens, and Rik Van de Walle: Low-Cost Queryable Linked Data through Triple Pattern Fragments. In Proceedings of the Demo Session at the 13th International Semantic Web Conference (ISWC), Riva del Garda, Trento, Italy, Oct. 2014 (Best Demo Award winner)
Olaf Hartig and Bryan Thompson: Foundations of an Alternative Approach to Reification in RDF. In CoRR abs/1406.3399, Jun. 2014
Olaf Hartig and M. Tamer Özsu: Linked Data Query Processing (Tutorial Description). Proceedings of the 30th International Conference on Data Engineering (ICDE), Chicago, IL, USA, Apr. 2014
Gunes Aluc, M. Tamer Özsu, Khuzaima Daudjee, and Olaf Hartig: chameleondb: a Workload-Aware Robust RDF Data Management System. In University of Waterloo Technical Report CS-2013-10, Sep. 2013
Olaf Hartig: SQUIN: A Traversal Based Query Execution System for the Web of Linked Data. Proceedings of the 2013 ACM SIGMOD International Conference on Management of Data, New York, USA, Jun. 2013
Graham Klyne, Paul Groth, Luc Moreau, Olaf Hartig, Yogesh Simmhan, James Myers, Timothy Lebo, Khalid Belhajjame, Simon Miles, and Stian Soiland-Reyes: PROV-AQ: Provenance Access and Query. W3C Working Group Note, Apr. 2013. Online at http://www.w3.org/TR/prov-aq/
Olaf Hartig: An Introduction to SPARQL and Queries over Linked Data (Tutorial Description). Proceedings of the 12th International Conference on Web Engineering (ICWE), Berlin, Germany, Jul. 2012
Olaf Hartig and Tom Heath: Query Prediction with Context Models for Populating Personal Linked Data Caches. Proceedings of the Poster Session at the 23rd ACM Conference on Hypertext and Social Media, Milwaukee, WI, USA, Jun. 2012
Olaf Hartig and Tom Heath: Populating Personal Linked Data Caches using Context Models. Proceedings of the Poster Session at the 21th International World Wide Web Conference (WWW), Lyon, France, Apr. 2012
Grigoris Antoniou, Oscar Corcho, Karl Aberer, Elena Simperl, and Rudi Studer (eds.): Semantic Data Management (Dagstuhl Seminar 12171). In Dagstuhl Reports, 2(4) Apr. 2012
James Cheney, Anthony Finkelstein, Bertram Ludaescher, and Stijn Vansummeren (eds.): Principles of Provenance (Dagstuhl Seminar 12091). In Dagstuhl Reports, 2(2) Feb. 2012
Juan Sequeda and Olaf Hartig: Towards a Query Language for the Web of Data (A Vision Paper). In CoRR abs/1110.3017, Oct. 2011
Olaf Hartig: Integrating Provenance into the Web of Data. In Nodalities Magazine, Issue 13, Spring 2011
Yolanda Gil, James Cheney, Paul Groth, Olaf Hartig, Simon Miles, Luc Moreau, and Paulo Pinheiro da Silva (eds.): Provenance XG Final Report. W3C Incubator Group Report, Dec. 2010. Online at http://www.w3.org/2005/Incubator/prov/XGR-prov/
Olaf Hartig and Jun Zhao: Integrating Provenance into the Web of Data. Proceedings of the Poster Session at the 7th Extended Semantic Web Conference (ESWC), Heraklion, Greece, Jun. 2010
Olaf Hartig, Jun Zhao, and Hannes Mühleisen: Automatic Integration of Metadata into the Web of Linked Data (Demonstration Proposal). Proceedings of the 2nd Workshop on Trust and Privacy on the Social and Semantic Web (SPOT) at the 7th Extended Semantic Web Conference (ESWC), Heraklion, Greece, May 2010
Olaf Hartig, Juan Sequeda, Jamie Taylor, and Patrick Sinclair: How to Consume Linked Data on the Web (Tutorial Description). Proceedings of the 19th International World Wide Web Conference (WWW), April 2010, Raleigh, NC, USA, Apr 2010
Olaf Hartig, Martin Kost, and Johann-Christoph Freytag: Designing Component-Based Semantic Web Applications with DESWAP. Proceedings of the Poster and Demonstration Session at the 7th International Semantic Web Conference (ISWC), Karlsruhe, Germany, Oct. 2008
Olaf Hartig: Grundlagen regelbasierter Optimierung für SPARQL. Diploma Thesis, Humboldt-Universität zu Berlin, 2006