@inproceedings{luis2013irregular,
title={Irregular sets of two-sided Birkhoff averages and hyperbolic sets},
author={Luis Barreira, Jinjun Li, and Claudia Valls},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203641322167089},
booktitle={Arkiv for Matematik},
volume={54},
number={1},
pages={13-30},
year={2013},
}

Luis Barreira, Jinjun Li, and Claudia Valls. Irregular sets of two-sided Birkhoff averages and hyperbolic sets. 2013. Vol. 54. In Arkiv for Matematik. pp.13-30. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203641322167089.