@article{AUPO_2002__41_1_a4,
     author = {Cz\'edli, G\'abor and Horv\'ath, Eszter K.},
     title = {Congruence distributivity and modularity permit tolerances},
     journal = {Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica},
     pages = {39--42},
     publisher = {mathdoc},
     volume = {41},
     number = {1},
     year = {2002},
     mrnumber = {1967338},
     zbl = {1043.08002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPO_2002__41_1_a4/}
}