Roberto Valenti Jacopo Staiano Nicu Sebe Theo Gevers Webcam-Based Visual Gaze Estimation. 662-671 2009 ICIAP http://dx.doi.org/10.1007/978-3-642-04146-4_71 conf/iciap/2009 db/conf/iciap/iciap2009.html#ValentiSSG09