@article{1103038897,
author = {Protter, M. H.},
title = {Vibration of a nonhomogeneous membrane.},
journal = {Pacific J. Math.},
volume = {9},
number = {4},
year = {1959},
pages = { 1249-1255},
language = {en},
url = {http://dml.mathdoc.fr/item/1103038897}
}
Protter, M. H. Vibration of a nonhomogeneous membrane.. Pacific J. Math., Tome 9 (1959) no. 4, pp. 1249-1255. http://gdmltest.u-ga.fr/item/1103038897/