Rainer Herpers L. Witta Jörg Bruske Gerald Sommer Dynamic Cell Structures for the Evaluation of Keypoints in Facial Images. 27-39 1997 8 Int. J. Neural Syst. 1 http://dx.doi.org/10.1142/S0129065797000057 db/journals/ijns/ijns8.html#HerpersWBS97