@article{104907, author = {Zden\v ek Hedrl\'\i n}, title = {On number of commutative mappings from finite set into itself (Preliminary communication)}, journal = {Commentationes Mathematicae Universitatis Carolinae}, volume = {003}, year = {1962}, pages = {32-32}, zbl = {0101.25202}, mrnumber = {0143708}, language = {en}, url = {http://dml.mathdoc.fr/item/104907} }
Hedrlín, Zdeněk. On number of commutative mappings from finite set into itself (Preliminary communication). Commentationes Mathematicae Universitatis Carolinae, Tome 003 (1962) p. 32. http://gdmltest.u-ga.fr/item/104907/