@article{CTGDC_1967__9_2_243_0,
     author = {Hilton, Peter},
     title = {Filtrations},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     pages = {243--253},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {9},
     number = {2},
     year = {1967},
     mrnumber = {228562},
     zbl = {0204.03003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CTGDC_1967__9_2_243_0/}
}