Matthias Kaschube Fred Wolf Theo Geisel Siegrid Löwel The prevalence of colinear contours in the real world. 1335-1339 2001 38-40 Neurocomputing http://dx.doi.org/10.1016/S0925-2312(01)00493-3 db/journals/ijon/ijon38.html#KaschubeWGL01