There are many references to k-means clustering. Those listed here had direct impact on our work.
[1] James Theiler and Galen Gisler, "A contiguity-enhanced k-means clustering algorithm for unsupervised multispectral image segmentation", Proc SPIE 3159. pgs 108--118, 1997. Available as postscript .
[2] Miriam Leeser , Natasha Kitaryeva, and Jill Crisman , "Spatial and Color Clustering on an FPGA-based Computer System" Proc SPIE Volume 3526, pgs 25-33, November 1998. Also available as Northeastern University technical report ECE-CEG-98-024. postscript
[3] On-line documentation for ENVI,the environment for Visualizing Images, available from Research Systems Inc. Especially the ENVI FAQ .