@article{1104250531,
author = {Ashbaugh, Mark S. and Benguria, Rafael D.},
title = {A second proof of the Payne-P\'olya-Weinberger conjecture},
journal = {Comm. Math. Phys.},
volume = {143},
number = {2},
year = {1992},
pages = { 181-190},
language = {en},
url = {http://dml.mathdoc.fr/item/1104250531}
}
Ashbaugh, Mark S.; Benguria, Rafael D. A second proof of the Payne-Pólya-Weinberger conjecture. Comm. Math. Phys., Tome 143 (1992) no. 2, pp. 181-190. http://gdmltest.u-ga.fr/item/1104250531/