@inproceedings{z.1982criteria,
title={Criteria for absolute convergence of multiple fourier series},
author={Z. Nowak},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203516496008402},
booktitle={Arkiv for Matematik},
volume={22},
number={1},
pages={25-32},
year={1982},
}