@article{CTGDC_1984__25_1_51_0,
     author = {MacDonald, John and Stone, Arthur},
     title = {Topoi over graphs},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     pages = {51--62},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {25},
     number = {1},
     year = {1984},
     mrnumber = {764971},
     zbl = {0546.18004},
     language = {en},
     url = {http://archive.numdam.org/item/CTGDC_1984__25_1_51_0/}
}