@article{1183493292,
author = {Davis, D. R.},
title = {The inverse problem of the calculus of variations in a space of $\left( {n + 1} \right)$ dimensions},
journal = {Bull. Amer. Math. Soc.},
volume = {35},
number = {6},
year = {1929},
pages = { 371-380},
language = {en},
url = {http://dml.mathdoc.fr/item/1183493292}
}
Davis, D. R. The inverse problem of the calculus of variations in a space of $\left( {n + 1} \right)$ dimensions. Bull. Amer. Math. Soc., Tome 35 (1929) no. 6, pp. 371-380. http://gdmltest.u-ga.fr/item/1183493292/