@article{CMUC_1967_8_4_a3,
     author = {Pultr, Ale\v{s} and Trnkov\'a, V\v{e}ra},
     title = {On realization and boundability of concrete categories in which the morphisms are choiced by local conditions},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {651--662},
     year = {1967},
     volume = {8},
     number = {4},
     mrnumber = {0231883},
     zbl = {0185.50402},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1967_8_4_a3/}
}