A. Geyer-Schulz. Genetic Algorithms and Soft Computing, volume 8 of Studies in Fuzziness and Soft Computing, page 658--682. Heidelberg, Physica-Verlag, (September 1996)
S. Lindley, J. Couteur, and N. Berthouze. (2008)From the 'I am here. Where are you?' session, at the 26th Annual CHI Conference on Human Factors in Computing Systems, April 5-10, 2008, Florence, Italy..