B. Elliott, E. Cheng, C. Thomas-Ogbuji, and Z. Ozsoyoglu. Proceedings of the 2009 International Database Engineering & Applications Symposium, page 31--42. New York, NY, USA, ACM, (2009)
D. Shahaf, C. Guestrin, and E. Horvitz. Proceedings of the 18th ACM SIGKDD international conference on Knowledge discovery and data mining, page 1122--1130. New York, NY, USA, ACM, (2012)