@inproceedings{thomas1984wiener's,
title={Wiener's criterion and obstacle problems for vector valued functions},
author={Thomas Karlsson},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203520797140436},
booktitle={Arkiv for Matematik},
volume={23},
number={1},
pages={315-325},
year={1984},
}
Thomas Karlsson. Wiener's criterion and obstacle problems for vector valued functions. 1984. Vol. 23. In Arkiv for Matematik. pp.315-325. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203520797140436.