Recursive estimation of facial expression and movement. - Haibo Li 001; Pertti Roivainen; Robert Forchheimer (ICASSP, 1992)

3-D Motion Estimation in Model-Based Facial Image Coding. - Haibo Li 001; Pertti Roivainen; Robert Forchheimer (IEEE Trans. Pattern Anal. Mach. Intell., 1993)

Using the potts glass for solving the clustering problem. - Mats Bengtsson; Pertti Roivainen (Int. J. Neural Syst., 1995)