@inproceedings{arne1971analytic,
title={Analytic continuation across a linear boundary},
author={Arne Beurling},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203224810659130},
booktitle={Acta Mathematica},
volume={128},
number={1},
pages={153-182},
year={1971},
}