@article{CTGDC_1981__22_2_191_0,
     author = {Porter, Timothy},
     title = {Une th\'eorie cat\'egorique d'homotopie simple},
     journal = {Cahiers de topologie et g\'eom\'etrie diff\'erentielle},
     pages = {191--199},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {22},
     number = {2},
     year = {1981},
     mrnumber = {649799},
     zbl = {0473.57010},
     language = {fr},
     url = {http://www.numdam.org/item/CTGDC_1981__22_2_191_0/}
}