@article{CTGDC_1993__34_3_239_0,
     author = {Trnkov\'a, V\v{e}ra},
     title = {Universal concrete categories and functors},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     pages = {239--256},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {34},
     number = {3},
     year = {1993},
     mrnumber = {1239471},
     zbl = {0797.18003},
     language = {en},
     url = {http://archive.numdam.org/item/CTGDC_1993__34_3_239_0/}
}