@article{1183500404, author = {Albert, A. Adrian}, title = {A quadratic form problem in the calculus of variations}, journal = {Bull. Amer. Math. Soc.}, volume = {44}, number = {11}, year = {1938}, pages = { 250-253}, language = {en}, url = {http://dml.mathdoc.fr/item/1183500404} }
Albert, A. Adrian. A quadratic form problem in the calculus of variations. Bull. Amer. Math. Soc., Tome 44 (1938) no. 11, pp. 250-253. http://gdmltest.u-ga.fr/item/1183500404/