@article{100403, author = {\v Stefan Schwarz}, title = {A theorem on normal semigroups}, journal = {Czechoslovak Mathematical Journal}, volume = {10}, year = {1960}, pages = {197-200}, zbl = {0098.01704}, mrnumber = {0116075}, language = {en}, url = {http://dml.mathdoc.fr/item/100403} }
Schwarz, Štefan. A theorem on normal semigroups. Czechoslovak Mathematical Journal, Tome 10 (1960) pp. 197-200. http://gdmltest.u-ga.fr/item/100403/
K teoriji hausdorfovych bikompaktnych polugrupp, (russian), Czechoslovak Math. J. 5 (80), 1955, 1-23. (1955) | MR 0074769