@article{1183487284,
author = {Douglas, Jesse},
title = {The transversality relative to a surface of $\int {F\left( {x,y,z,y',z'} \right)dx = {\text{Minimum}}}$},
journal = {Bull. Amer. Math. Soc.},
volume = {32},
number = {5},
year = {1926},
pages = { 669-674},
language = {en},
url = {http://dml.mathdoc.fr/item/1183487284}
}
Douglas, Jesse. The transversality relative to a surface of $\int {F\left( {x,y,z,y',z'} \right)dx = {\text{Minimum}}}$. Bull. Amer. Math. Soc., Tome 32 (1926) no. 5, pp. 669-674. http://gdmltest.u-ga.fr/item/1183487284/