@inproceedings{n.1965half-order,
title={Half-order differentials on Riemann surfaces},
author={N. S. Hawley, and M. Schiffer},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203208499187010},
booktitle={Acta Mathematica},
volume={115},
number={1},
pages={199-236},
year={1965},
}