@article{1183419222,
author = {Kasner, Edward},
title = {Systems of extremals in the calculus of variations},
journal = {Bull. Amer. Math. Soc.},
volume = {14},
number = {3},
year = {1907},
pages = { 289-292},
language = {en},
url = {http://dml.mathdoc.fr/item/1183419222}
}
Kasner, Edward. Systems of extremals in the calculus of variations. Bull. Amer. Math. Soc., Tome 14 (1907) no. 3, pp. 289-292. http://gdmltest.u-ga.fr/item/1183419222/