T. Chin, \. Bustos, M. Brown, and D. Suter. Proceedings of the 18th Meeting of the ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, page 55--62. New York, NY, USA, ACM, (2014)
S. Garcia Esparza, M. O'Mahony, and B. Smyth. RecSys'10 : proceedings of the 4th ACM Conference on Recommender Systems, Barcelona, Spain, September 26-30, 2010, (2010)