Arantxa Villanueva Rafael Cabeza A Novel Gaze Estimation System With One Calibration Point. 1123-1138 2008 38 IEEE Transactions on Systems, Man, and Cybernetics, Part B 4 http://dx.doi.org/10.1109/TSMCB.2008.926606 db/journals/tsmc/tsmcb38.html#VillanuevaC08