@article{DIA_1979__2__A4_0,
     author = {Penon, J.},
     title = {Th\'eories de cat\'egories},
     journal = {Diagrammes},
     note = {talk:4},
     pages = {P1--P54},
     publisher = {Universit\'e Paris 7, Unit\'e d'enseignement et de recherche de math\'ematiques},
     volume = {2},
     year = {1979},
     mrnumber = {685050},
     zbl = {0518.18010},
     language = {fr},
     url = {http://www.numdam.org/item/DIA_1979__2__A4_0/}
}