@article{SE_1964__6__A8_0,
     author = {Ehresmann, Charles},
     title = {Cat\'egories et structures : extraits},
     journal = {S\'eminaire Ehresmann. Topologie et g\'eom\'etrie diff\'erentielle},
     note = {talk:8},
     pages = {1--31},
     publisher = {Secr\'etariat math\'ematique},
     volume = {6},
     year = {1964},
     mrnumber = {197530},
     zbl = {0282.18008},
     language = {fr},
     url = {http://archive.numdam.org/item/SE_1964__6__A8_0/}
}