@article{CTGDC_1966__8__A1_0,
     author = {Ehresmann, Charles},
     title = {Trends toward unity in mathematics},
     journal = {Cahiers de topologie et g\'eom\'etrie diff\'erentielle},
     note = {talk:1},
     pages = {1--7},
     publisher = {CNRS},
     volume = {8},
     year = {1966},
     zbl = {0147.24103},
     language = {en},
     url = {http://archive.numdam.org/item/CTGDC_1966__8__A1_0/}
}