@article{GDZPPN002426005,
title = {On the Principal Eigenvalue of a Second Order Linear Elliptic Problem with an Indefinite Weight Function.},
journal = {Mathematische Zeitschrift},
volume = {180},
year = {1982},
pages = {237-240},
zbl = {0461.35066},
url = {http://dml.mathdoc.fr/item/GDZPPN002426005}
}
Hess, Peter. On the Principal Eigenvalue of a Second Order Linear Elliptic Problem with an Indefinite Weight Function.. Mathematische Zeitschrift, Tome 180 (1982) pp. 237-240. http://gdmltest.u-ga.fr/item/GDZPPN002426005/