@article{10_21136_CMJ_1951_100013,
     author = {Schwarz, \v{S}tefan},
     title = {On the structure of simple semigroups without zero},
     journal = {Czechoslovak Mathematical Journal},
     pages = {41--53},
     year = {1951},
     volume = {1},
     number = {1},
     doi = {10.21136/CMJ.1951.100013},
     mrnumber = {0048428},
     zbl = {0045.15608},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1951.100013/}
}