@article{CMUC_1976__17_3_a8,
     author = {Trnkov\'a, V\v{e}ra},
     title = {On products of binary relational structures},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {513--521},
     publisher = {mathdoc},
     volume = {17},
     number = {3},
     year = {1976},
     mrnumber = {0424642},
     zbl = {0361.08002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1976__17_3_a8/}
}