@article{CTGDC_1986__27_2_151_0,
     author = {Castellini, Gabriele},
     title = {Closure operators, monomorphisms and epimorphisms in categories of groups},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     pages = {151--167},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {27},
     number = {2},
     year = {1986},
     mrnumber = {850530},
     zbl = {0592.18001},
     language = {en},
     url = {http://www.numdam.org/item/CTGDC_1986__27_2_151_0/}
}