B. Hecht, and D. Gergle. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (CHI '10), Atlanta, GA, USA, page 291--300. New York, ACM, (2010)
S. Zhang, and S. Goddard. International Conference on Information Technology: Coding and Computing, 2005. ITCC 2005, 2, page 443-- 448 Vol. 2. IEEE, (April 2005)