@inproceedings{d.1965curves, title={Curves on 2-manifolds: A counterexample}, author={D. B. A. Epstein, and H. Zieschang}, url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203208039877006}, booktitle={Acta Mathematica}, volume={115}, number={1}, pages={109-110}, year={1965}, }