H. Aher, P. Shirode, K. Shinde, und A. Jadhav. International Journal on Recent and Innovation Trends in Computing and Communication, 3 (1):
46--51(Januar 2015)
M. Welch, U. Schonfeld, D. He, und J. Cho. Proceedings of the fourth ACM international conference on Web search and data mining, Seite 327--336. New York, NY, USA, ACM, (2011)