@inproceedings{lars1980on,
title={On polyharmonic continuation by reflection formulas},
author={Lars Nystedt},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203513305470375},
booktitle={Arkiv for Matematik},
volume={20},
number={1},
pages={201-247},
year={1980},
}