@article{JMPA_1842_1_7__55_0, author = {Bertrand, J.}, title = {Note sur un point du calcul des variations}, journal = {Journal de Math\'ematiques Pures et Appliqu\'ees}, pages = {55--58}, publisher = {Gauthier-Villars}, volume = {1e s{\'e}rie, 7}, year = {1842}, language = {fr}, url = {http://archive.numdam.org/item/JMPA_1842_1_7__55_0/} }