@article{1077304285,
author = {Phillips, R. S. and Sarnak, P.},
title = {On the spectrum of the Hecke groups},
journal = {Duke Math. J.},
volume = {52},
number = {1},
year = {1985},
pages = { 211-221},
language = {en},
url = {http://dml.mathdoc.fr/item/1077304285}
}
Phillips, R. S.; Sarnak, P. On the spectrum of the Hecke groups. Duke Math. J., Tome 52 (1985) no. 1, pp. 211-221. http://gdmltest.u-ga.fr/item/1077304285/