@article{CMUC_1973__14_1_a3,
     author = {Koubek, V\'aclav},
     title = {Set functor. {II:} {Contravariant} case},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {47--59},
     publisher = {mathdoc},
     volume = {14},
     number = {1},
     year = {1973},
     mrnumber = {0318257},
     zbl = {0256.18003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1973__14_1_a3/}
}