@inproceedings{r.1887zur,
title={Zur Theorie der Krummen Oberflächen},
author={R. Lipschitz},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108202941695702851},
booktitle={Acta Mathematica},
volume={10},
number={1},
pages={131-136},
year={1887},
}