@inproceedings{gunnar1971hardy-fields,
title={Hardy-fields},
author={Gunnar Sjödin},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203444989846135},
booktitle={Arkiv for Matematik},
volume={8},
number={3},
pages={217-237},
year={1971},
}