Mika S, Schölkopf, B Department Empirical Inference, Max Planck Institute for Biological Cybernetics, Max Planck Society;
Smola, A., Mika S, Schölkopf, B., & Williamson, R. (2001). Regularized principal manifolds. Journal of Machine Learning Research, 1, 179-209. Retrieved from http://jmlr.csail.mit.edu/papers/volume1/smola01a/smola01a.pdf.