@article{CMUC_1981__22_2_a1,
     author = {Je\v{z}ek, Jaroslav and Kepka, Tom\'a\v{s}},
     title = {Free entropic groupoids},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {223--233},
     publisher = {mathdoc},
     volume = {22},
     number = {2},
     year = {1981},
     mrnumber = {620359},
     zbl = {0464.08004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1981__22_2_a1/}
}