@inproceedings{frédéric1938les,
title={Les proprietes tangentielles des ensembles euclidiens de points},
author={Frédéric Roger},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203112043958589},
booktitle={Acta Mathematica},
volume={69},
number={1},
pages={99-133},
year={1938},
}