Luc Hoegaerts Johan A. K. Suykens Joos Vandewalle Bart De Moor Subset based least squares subspace regression in RKHS. 293-323 2005 63 Neurocomputing http://dx.doi.org/10.1016/j.neucom.2004.04.013 db/journals/ijon/ijon63.html#HoegaertsSVM05