@article{1183499833,
author = {Ewing, G. M.},
title = {Sufficient conditions for a non-regular problem in the calculus of variations},
journal = {Bull. Amer. Math. Soc.},
volume = {43},
number = {12},
year = {1937},
pages = { 371-376},
language = {en},
url = {http://dml.mathdoc.fr/item/1183499833}
}
Ewing, G. M. Sufficient conditions for a non-regular problem in the calculus of variations. Bull. Amer. Math. Soc., Tome 43 (1937) no. 12, pp. 371-376. http://gdmltest.u-ga.fr/item/1183499833/