@article{CMUC_1968_9_1_a18,
     author = {Kat\v{e}tov, Miroslav},
     title = {Products of filters},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {173--189},
     year = {1968},
     volume = {9},
     number = {1},
     mrnumber = {0250257},
     zbl = {0155.50301},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1968_9_1_a18/}
}