@article{CMUC_1971__12_1_a15,
     author = {Koubek, V\'aclav},
     title = {Set functors},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {175--195},
     publisher = {mathdoc},
     volume = {12},
     number = {1},
     year = {1971},
     mrnumber = {0286860},
     zbl = {0217.06803},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1971__12_1_a15/}
}