@article{MASLO_1973__23_3_a7,
     author = {Pond\v{e}l{\'\i}\v{c}ek, Bed\v{r}ich},
     title = {A {Relation} for {Closure} {Operations} on a {Semigroup}},
     journal = {Mathematica slovaca},
     pages = {249--256},
     publisher = {mathdoc},
     volume = {23},
     number = {3},
     year = {1973},
     mrnumber = {0364509},
     zbl = {0265.20053},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MASLO_1973__23_3_a7/}
}