@article{GDZPPN002203324,
title = {Cohomology of arithmetic groups and congruences between systems of Hecke eigenvalues.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {372},
year = {1986},
pages = {192-220},
zbl = {0596.10026},
url = {http://dml.mathdoc.fr/item/GDZPPN002203324}
}
Ash, Avner; Stevens, Glenn. Cohomology of arithmetic groups and congruences between systems of Hecke eigenvalues.. Journal für die reine und angewandte Mathematik, Tome 372 (1986) pp. 192-220. http://gdmltest.u-ga.fr/item/GDZPPN002203324/