@inproceedings{åke1961on,
title={On the boundary behavior of the derivative of analytic functions},
author={Åke Samuelsson},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203425852895970},
booktitle={Arkiv for Matematik},
volume={4},
number={2},
pages={219-230},
year={1961},
}
Åke Samuelsson. On the boundary behavior of the derivative of analytic functions. 1961. Vol. 4. In Arkiv for Matematik. pp.219-230. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203425852895970.