@article{1183532102,
author = {Berger, Melvyn S.},
title = {On Morse theory and stationary states for nonlinear wave equations},
journal = {Bull. Amer. Math. Soc.},
volume = {76},
number = {4},
year = {1970},
pages = { 827-829},
language = {en},
url = {http://dml.mathdoc.fr/item/1183532102}
}
Berger, Melvyn S. On Morse theory and stationary states for nonlinear wave equations. Bull. Amer. Math. Soc., Tome 76 (1970) no. 4, pp. 827-829. http://gdmltest.u-ga.fr/item/1183532102/