@article{10_21136_MB_1991_126027,
     author = {Pond\v{e}l{\'\i}\v{c}ek, Bed\v{r}ich},
     title = {On permutability in semigroup varieties},
     journal = {Mathematica Bohemica},
     pages = {396--400},
     publisher = {mathdoc},
     volume = {116},
     number = {4},
     year = {1991},
     doi = {10.21136/MB.1991.126027},
     mrnumber = {1146398},
     zbl = {0746.20034},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/MB.1991.126027/}
}