Annika Kuhl Lars Krüger Christian Wöhler Ulrich Kressel Training of Classifiers Using Virtual Samples Only. 418-421 2004 ICPR (3) http://doi.ieeecomputersociety.org/10.1109/ICPR.2004.951 db/conf/icpr/icpr2004-3.html#KuhlKWK04