F. Vitali, A. Iorio, and J. Blustein. HT '09: Proceedings of the Twentieth ACM Conference on Hypertext and Hypermedia, New York, NY, USA, ACM, (July 2009)
N. Anderson, and C. Lin. ITiCSE '09: Proceedings of the 14th annual ACM SIGCSE conference on Innovation and technology in computer science education, page 243--247. New York, NY, USA, ACM, (2009)
J. Leskovec, L. Backstrom, and J. Kleinberg. KDD '09: Proceedings of the 15th ACM SIGKDD international conference on Knowledge discovery and data mining, page 497--506. New York, NY, USA, ACM, (2009)
N. Aizenbud-Reshef, I. Guy, and M. Jacovi. GROUP '09: Proceedings of the ACM 2009 international conference on Supporting group work, page 277--280. New York, NY, USA, ACM, (2009)