@article{01779096,
title = {Boundedness and monotonicity of principal eigenvalues for boundary value problems with indefinite weight functions.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {30},
year = {2002},
pages = {25-29},
doi = {10.1155/S0161171202007780},
zbl = {1005.35033},
language = {en},
url = {http://dml.mathdoc.fr/item/01779096}
}
Afrouzi, G.A. Boundedness and monotonicity of principal eigenvalues for boundary value problems with indefinite weight functions.. International Journal of Mathematics and Mathematical Sciences, Tome 30 (2002) pp. 25-29. doi : 10.1155/S0161171202007780. http://gdmltest.u-ga.fr/item/01779096/