Zoltan is the original one... there's a lot of CSP references.
I used two paper from Lotte and Blankertz to develop the code :
F. Lotte, C.T. Guan, "Regularizing Common Spatial Patterns to Improve BCI Designs: Unified Theory and New Algorithms", IEEE Transactions on Biomedical Engineering, vol. 58, no. 2, pp. 355-362, 2011
Blankertz, B.; Tomioka, R.; Lemm, S.; Kawanabe, M.; Muller, K.-R., "Optimizing Spatial filters for Robust EEG Single-Trial Analysis," Signal Processing Magazine, IEEE , vol.25, no.1, pp.41,56, 2008