@article{CMJ_2000_50_1_a5,
     author = {Zelinka, Bohdan},
     title = {On a problem concerning stratified graphs},
     journal = {Czechoslovak Mathematical Journal},
     pages = {47--49},
     year = {2000},
     volume = {50},
     number = {1},
     mrnumber = {1745457},
     zbl = {1033.05035},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2000_50_1_a5/}
}