@article{10_21136_CPM_1966_117557,
     author = {Zelinka, Bohdan},
     title = {Pologrupa nepr\'azdn\'ych podmno\v{z}in cyklick\'e pologrupy},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky},
     pages = {72--76},
     year = {1966},
     volume = {91},
     number = {1},
     doi = {10.21136/CPM.1966.117557},
     mrnumber = {0197612},
     zbl = {0143.03401},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPM.1966.117557/}
}