@article{article9facd39e,
title   = {On the spectrum of a evolution operators generated by hiperbolic systems},
author = {Neves, Aloisio Freiria and Ribeiro, Hermano de Souza and Lopes, Orlando},
year = {1986},
doi = {10.1016/0022-1236(86)90029-7},
journal   = {Journal of Functional Analysis}
}