@article{JMPA_1836_1_1__317_0,
     author = {Saint-Guilhem},
     title = {Note relative \`a la d\'etermination des plans principaux d'une surface du second degr\'e rapport\'ee \`a trois axes quelconques},
     journal = {Journal de Math\'ematiques Pures et Appliqu\'ees},
     pages = {317--323},
     publisher = {Gauthier-Villars},
     volume = {1e s{\'e}rie, 1},
     year = {1836},
     language = {fr},
     url = {http://www.numdam.org/item/JMPA_1836_1_1__317_0/}
}