@article{GDZPPN002063557,
title = {Extremal eigenvalue problems defined on conformal classes of compact Riemannian manifolds.},
journal = {Commentarii mathematici Helvetici},
volume = {54},
year = {1979},
pages = {494-507},
zbl = {0418.58017},
url = {http://dml.mathdoc.fr/item/GDZPPN002063557}
}
Friedland, Shmuel. Extremal eigenvalue problems defined on conformal classes of compact Riemannian manifolds.. Commentarii mathematici Helvetici, Tome 54 (1979) pp. 494-507. http://gdmltest.u-ga.fr/item/GDZPPN002063557/