@article{CMUC_1970__11_1_a2,
     author = {Koubek, V\'aclav and Reiterman, Jan},
     title = {On the category of filters},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {19--29},
     publisher = {mathdoc},
     volume = {11},
     number = {1},
     year = {1970},
     mrnumber = {0262141},
     zbl = {0199.33102},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1970__11_1_a2/}
}