@article{10_21136_CMJ_1991_102442,
     author = {Duda, Jarom{\'\i}r},
     title = {Conditions for factorable relations},
     journal = {Czechoslovak Mathematical Journal},
     pages = {131--134},
     publisher = {mathdoc},
     volume = {41},
     number = {1},
     year = {1991},
     doi = {10.21136/CMJ.1991.102442},
     mrnumber = {1087632},
     zbl = {0795.08007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1991.102442/}
}