@article{105283, author = {Jaroslav Draho\v s}, title = {Modifications of closure collections}, journal = {Commentationes Mathematicae Universitatis Carolinae}, volume = {011}, year = {1970}, pages = {379-384}, zbl = {0197.18801}, mrnumber = {0266202}, language = {en}, url = {http://dml.mathdoc.fr/item/105283} }
Drahoš, Jaroslav. Modifications of closure collections. Commentationes Mathematicae Universitatis Carolinae, Tome 011 (1970) pp. 379-384. http://gdmltest.u-ga.fr/item/105283/
Structure projective and structure inductive presheaves, Celebrazioni archimedee del secolo XX: Simposio di topologia, 1964. (1964)