F. Abel, N. Henze, and D. Krause. CIKM '08: Proceeding of the 17th ACM conference on Information and knowledge mining, page 1429--1430. New York, NY, USA, ACM, (2008)
F. Abel, N. Henze, and D. Krause. Proceeding of the 17th ACM conference on Information and knowledge management, page 1429--1430. New York, NY, USA, ACM, (2008)
D. Abrams, R. Baecker, and M. Chignell. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, page 41--48. New York, NY, USA, ACM Press/Addison-Wesley Publishing Co., (1998)
Y. Ahn, S. Han, H. Kwak, S. Moon, and H. Jeong. WWW '07: Proceedings of the 16th international conference on World Wide Web, page 835--844. New York, NY, USA, ACM, (2007)