@article{BSMF_1933__61__95_0,
     author = {Delens, Paul},
     title = {G\'eom\'etrie conforme des congruences de courbes},
     journal = {Bulletin de la Soci\'et\'e Math\'ematique de France},
     pages = {95--127},
     publisher = {Soci\'et\'e math\'ematique de France},
     volume = {61},
     year = {1933},
     doi = {10.24033/bsmf.1199},
     zbl = {0007.07901},
     language = {fr},
     url = {http://www.numdam.org/articles/10.24033/bsmf.1199/}
}