@article{10_21136_CMJ_1991_102446,
     author = {Duda, Jarom{\'\i}r},
     title = {Relation products of congruences and factor congruences},
     journal = {Czechoslovak Mathematical Journal},
     pages = {155--159},
     publisher = {mathdoc},
     volume = {41},
     number = {1},
     year = {1991},
     doi = {10.21136/CMJ.1991.102446},
     mrnumber = {1087636},
     zbl = {0790.08001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1991.102446/}
}