@article{GDZPPN00210699X,
title = {Differentiability and analycity of topological entropy for Anosov and geodesic flows.},
journal = {Inventiones mathematicae},
volume = {96},
year = {1989},
pages = {581-598},
zbl = {0702.58053},
url = {http://dml.mathdoc.fr/item/GDZPPN00210699X}
}
Katok, A.; Pollicott, M.; Knieper, G. Differentiability and analycity of topological entropy for Anosov and geodesic flows.. Inventiones mathematicae, Tome 96 (1989) pp. 581-598. http://gdmltest.u-ga.fr/item/GDZPPN00210699X/