- (2010)
- (2004)
- Proceedings on the W3C Workshop on the Future of Social Networking, (2009)
- Decision Support Systems 43(2):460 - 475 (2007)Emerging Issues in Collaborative Commerce .
- SIGMOD '07: Proceedings of the 2007 ACM SIGMOD international conference on Management of data, page 1097--1099. New York, NY, USA, ACM, (2007)
- (2000)
- (2004)
- (2004)
- Tilburg University, Tilburg, The Netherlands, (December 2009)
- Personal and Ubiquitous Computing 12(7):527-542 (2008)
- Science 327(5968):1018--1021 (2010)
- Telemática Institut, Enschede, The Netherlands, (1998)


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