@article{1102635617,
author = {Engman, Martin},
title = {New spectral characterization theorems for $S^2$.},
journal = {Pacific J. Math.},
volume = {156},
number = {2},
year = {1992},
pages = { 215-229},
language = {en},
url = {http://dml.mathdoc.fr/item/1102635617}
}
Engman, Martin. New spectral characterization theorems for $S^2$.. Pacific J. Math., Tome 156 (1992) no. 2, pp. 215-229. http://gdmltest.u-ga.fr/item/1102635617/