@inproceedings{nils1998estimates,
title={Estimates and solvability},
author={Nils Dencker},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203555726729722},
booktitle={Arkiv for Matematik},
volume={37},
number={2},
pages={221-243},
year={1998},
}