@inproceedings{f.1890mesure, title={Mesure de la courbure des surfaces suivant l'idée commune.}, author={F. Casorati}, url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108202950901131935}, booktitle={Acta Mathematica}, volume={14}, number={1}, pages={95-110}, year={1890}, }