@article{1256054459,
author = {Beals, Richard},
title = {On eigenfunction expansions for elliptic operators},
journal = {Illinois J. Math.},
volume = {11},
number = {4},
year = {1967},
pages = { 663-668},
language = {en},
url = {http://dml.mathdoc.fr/item/1256054459}
}
Beals, Richard. On eigenfunction expansions for elliptic operators. Illinois J. Math., Tome 11 (1967) no. 4, pp. 663-668. http://gdmltest.u-ga.fr/item/1256054459/