Nicolas Pérez de la Blanca José M. Fuertes Manuel J. Lucena 3D Rigid Facial Motion Estimation from Disparity Maps. 54-61 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2905&spage=54 2003 conf/ciarp/2003 CIARP db/conf/ciarp/ciarp2003.html#BlancaFL03