%0 Journal Article %A Trnková, Věra %T Strong embedding of category of all groupoids into category of semigroups %J Commentationes Mathematicae Universitatis Carolinae %D 1968 %P 251-256 %V 9 %N 2 %U http://geodesic.mathdoc.fr/item/CMUC_1968_9_2_a5/ %G en %F CMUC_1968_9_2_a5