@article{1183533160,
author = {Hopf, Eberhard},
title = {Ergodic theory and the geodesic flow on surfaces of constant negative curvature},
journal = {Bull. Amer. Math. Soc.},
volume = {77},
number = {6},
year = {1971},
pages = { 863-877},
language = {en},
url = {http://dml.mathdoc.fr/item/1183533160}
}
Hopf, Eberhard. Ergodic theory and the geodesic flow on surfaces of constant negative curvature. Bull. Amer. Math. Soc., Tome 77 (1971) no. 6, pp. 863-877. http://gdmltest.u-ga.fr/item/1183533160/