@article{10_21136_CMJ_1990_102413,
     author = {Chajda, Ivan},
     title = {On the existence of non-trivial tolerances in permutable algebras},
     journal = {Czechoslovak Mathematical Journal},
     pages = {598--600},
     publisher = {mathdoc},
     volume = {40},
     number = {4},
     year = {1990},
     doi = {10.21136/CMJ.1990.102413},
     mrnumber = {1084895},
     zbl = {0742.08002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1990.102413/}
}