@article{CTGDC_2009__50_2_144_0,
     author = {Guitart, Ren\'e},
     title = {Klein's group as a borromean object},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     eid = {3},
     pages = {144--155},
     publisher = {Andr\'ee CHARLES EHRESMANN},
     volume = {50},
     number = {2},
     year = {2009},
     mrnumber = {2535164},
     zbl = {1186.18002},
     language = {en},
     url = {http://www.numdam.org/item/CTGDC_2009__50_2_144_0/}
}