@article{GDZPPN002095203,
title = {Critical Point Theorems for Indefinite Functionals.},
journal = {Inventiones mathematicae},
volume = {55},
year = {1979},
pages = {241-274},
zbl = {0465.49006},
url = {http://dml.mathdoc.fr/item/GDZPPN002095203}
}
Benci, Vieri; Rabinowitz, Paul H. Critical Point Theorems for Indefinite Functionals.. Inventiones mathematicae, Tome 55 (1979) pp. 241-274. http://gdmltest.u-ga.fr/item/GDZPPN002095203/