@inproceedings{arne1964a,
title={A critical topology in harmonic analysis on semigroups},
author={Arne Beurling},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203205057108985},
booktitle={Acta Mathematica},
volume={112},
number={1},
pages={215-228},
year={1964},
}