@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/