@article{1183418729,
author = {Hedrick, E. R.},
title = {The new calculus of variations},
journal = {Bull. Amer. Math. Soc.},
volume = {13},
number = {3},
year = {1906},
pages = { 172-181},
language = {en},
url = {http://dml.mathdoc.fr/item/1183418729}
}
Hedrick, E. R. The new calculus of variations. Bull. Amer. Math. Soc., Tome 13 (1906) no. 3, pp. 172-181. http://gdmltest.u-ga.fr/item/1183418729/