user- CHI '06: Proceedings of the SIGCHI conference on Human Factors in computing systems, page 711--720. New York, NY, USA, ACM Press, (2006)
- (2008)
- JCDL '07: Proceedings of the 2007 conference on Digital libraries, page 442--451. New York, NY, USA, ACM Press, (2007)
- CHI '08: Proceeding of the twenty-sixth annual SIGCHI conference on Human factors in computing systems, page 1353--1356. New York, NY, USA, ACM, (2008)
- CHI '03: Proceedings of the conference on Human factors in computing systems, page 401--408. ACM Press, (2003)
- Commun. ACM 49(4):59--61 (April 2006)
- Journal of Digital Information (2003)
- JCDL '08: Proceedings of the 8th ACM/IEEE-CS joint conference on Digital libraries, page 420. New York, NY, USA, ACM, (2008)
- WWW '07: Proceedings of the 16th international conference on World Wide Web, page 1311--1312. New York, NY, USA, ACM, (2007)
- WWW '08: Proceeding of the 17th international conference on World Wide Web, page 477--486. New York, NY, USA, ACM, (2008)
- GIR '08: Proceeding of the 2nd international workshop on Geographic information retrieval, page 55--56. New York, NY, USA, ACM, (2008)
- Proc. of the Collaborative Web Tagging Workshop WWW '06, (May 2006)
