@article{10_21136_CMJ_1983_101905,
     author = {Chajda, Ivan and Rach\r{u}nek, Ji\v{r}{\'\i}},
     title = {Relational characterizations of permutable and $n$-permutable varieties},
     journal = {Czechoslovak Mathematical Journal},
     pages = {505--508},
     publisher = {mathdoc},
     volume = {33},
     number = {4},
     year = {1983},
     doi = {10.21136/CMJ.1983.101905},
     mrnumber = {721079},
     zbl = {0545.08011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1983.101905/}
}