PHASE: a new engine for pharmacophore perception, 3D QSAR model development, and 3D database screening: 1. Methodology and preliminary results. - Steven L. Dixon; Alexander M. Smondyrev; Eric H. Knoll; Shashidhar N. Rao; David E. Shaw; Richard A. Friesner (J. Comput. Aided Mol. Des., 2006)