First steps towards automatic recognition of spontaneous facial action units. - Bjorn Braathen; Marian Stewart Bartlett; Gwen Littlewort; Javier R. Movellan (PUI, 2001)

An Approach to Automatic Recognition of Spontaneous Facial Actions. - Bjorn Braathen; Marian Stewart Bartlett; Gwen Littlewort; Evan Smith; Javier R. Movellan (FGR, 2002)

A Prototype for Automatic Recognition of Spontaneous Facial Actions. - Marian Stewart Bartlett; Gwen Littlewort; Bjorn Braathen; Terrence J. Sejnowski; Javier R. Movellan (NIPS, 2002)