@inproceedings{evgeny2009k-normal, title={k-NORMAL SURFACES}, author={Evgeny Fominykh, and Bruno Martelli}, url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20160911182605392030770}, booktitle={Journal of Differential Geometry}, volume={82}, number={1}, pages={101-114}, year={2009}, }