@inproceedings{ingemar1965a,
title={A strong form of spectral synthesis},
author={Ingemar Wik},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203433850235040},
booktitle={Arkiv for Matematik},
volume={6},
number={1},
pages={55-64},
year={1965},
}