@inproceedings{buchin1951extremal,
title={Extremal deviation in a geometry based on the notion of area},
author={Buchin Su},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203131320438731},
booktitle={Acta Mathematica},
volume={85},
number={1},
pages={99-116},
year={1951},
}