@inproceedings{harold1970the,
title={The maximum principle for multiple-valued analytic functions},
author={Harold Widom},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203221391831106},
booktitle={Acta Mathematica},
volume={126},
number={1},
pages={63-82},
year={1970},
}