@article{GDZPPN002195658,
title = {Poincar\'e series and negatively curved manifolds.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {310},
year = {1979},
pages = {77-81},
zbl = {0397.53033},
url = {http://dml.mathdoc.fr/item/GDZPPN002195658}
}
Chen, Su-shing. Poincaré series and negatively curved manifolds.. Journal für die reine und angewandte Mathematik, Tome 310 (1979) pp. 77-81. http://gdmltest.u-ga.fr/item/GDZPPN002195658/