@article{1183423204,
author = {Fischer, Charles Albert},
title = {The Legendre condition for a minimum of a double integral with an isoperimetric condition},
journal = {Bull. Amer. Math. Soc.},
volume = {22},
number = {3},
year = {1915},
pages = { 380-387},
language = {en},
url = {http://dml.mathdoc.fr/item/1183423204}
}
Fischer, Charles Albert. The Legendre condition for a minimum of a double integral with an isoperimetric condition. Bull. Amer. Math. Soc., Tome 22 (1915) no. 3, pp. 380-387. http://gdmltest.u-ga.fr/item/1183423204/