@inproceedings{yong2000menger,
title={Menger curvature and C^1 regularity of fractals},
author={Yong Lin, and Pertti Mattila},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20220707110012179075547},
booktitle={Proceeding of American Mathematics Society},
volume={129},
number={6},
pages={1755-1762},
year={2000},
}

Yong Lin, and Pertti Mattila. Menger curvature and C^1 regularity of fractals. 2000. Vol. 129. In Proceeding of American Mathematics Society. pp.1755-1762. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20220707110012179075547.