S. Ben-Yacoub Juergen Luettin Kenneth Jonsson Jiri Matas Josef Kittler Audio-Visual Person Verification. 1580-1585 1999 conf/cvpr/1999 CVPR http://doi.ieeecomputersociety.org/10.1109/CVPR.1999.786997 db/conf/cvpr/cvpr1999.html#Ben-YacoubLJMK99