MathSciDoc: An Archive for Mathematician ∫

@inproceedings{h.1966on,
  title={On modifications of Riemann surfaces},
  author={H. Renggli},
  url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203435618541054},
  booktitle={Arkiv for Matematik},
  volume={6},
  number={4},
  pages={299-306},
  year={1966},
}