@article{CMUC_1971__12_1_a12,
     author = {Pechanec-Draho\v{s}, Jaroslav},
     title = {A construction of the projective modification for a closure-set of a presheaf},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {117--125},
     publisher = {mathdoc},
     volume = {12},
     number = {1},
     year = {1971},
     mrnumber = {0286061},
     zbl = {0216.18903},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1971__12_1_a12/}
}