@inproceedings{,
title={Etude du cas où il n'y a que deux degrés de liberté},
author={},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108202949336064921},
booktitle={Acta Mathematica},
volume={13},
number={1},
pages={166-180},
year={1890},
}