Theresa Cooke Florian Steinke Christian Wallraven Heinrich H. Bülthoff A similarity-based approach to perceptual feature validation. 59-66 2005 APGV http://doi.acm.org/10.1145/1080402.1080413 conf/apgv/2005 db/conf/apgv/apgv2005.html#CookeSWB05