Ana Maria Mendonça Aurélio C. Campilho José Manuel Rodrigues Nunes A New Similarity Criterion for Retinal Image Registration. 696-700 1994 conf/icip/1994 ICIP (3) db/conf/icip/icip1994-3.html#MendoncaCN94 http://dx.doi.org/10.1109/ICIP.1994.413799