B. Tan, A. Velivelli, H. Fang, and C. Zhai. SIGIR '07: Proceedings of the 30th annual international ACM SIGIR conference on Research and development in information retrieval, page 263--270. New York, NY, USA, ACM Press, (2007)
R. Aler, D. Borrajo, and P. Isasi. Proceedings of the 2001 Congress on Evolutionary
Computation CEC2001, page 1220--1227. COEX, World Trade Center, 159 Samseong-dong,
Gangnam-gu, Seoul, Korea, IEEE Press, (27-30 May 2001)
R. Popp, D. Montana, R. Gassner, G. Vidaver, and S. Iyer. IEEE International Conference on Systems, Man, and
Cybernetics, 3, page 2184--2189. San Diego, CA USA, IEEE, (11-14 October 1998)