James G. Lefevre Diane Donovan Ales Drápal Permutation Representation of 3 and 4-Homogenous Latin Bitrades. 99-110 2008 84 Fundam. Inform. 1 http://iospress.metapress.com/content/8855782v65885474/ db/journals/fuin/fuin84.html#LefevreDD08