A. Di Ciaccio, and G. Bove. Fifth international symposium on data analysis and informatics, Vol. 2., page 137--145. Versailles, France, (Date unknown 1987)
J. Carroll, and A. Chaturvedi. Geometric representations of perceptual phenomena: Papers in honor of Tarow Indow on his 70th birthday., Erlbaum, Mahwah, NJ, (1995)