@inproceedings{n.1987the,
title={The propagation of singularities for pseudo-differential operators with self-tangential characteristics},
author={N. Dencker},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203528847912502},
booktitle={Arkiv for Matematik},
volume={27},
number={1},
pages={65-88},
year={1987},
}
N. Dencker. The propagation of singularities for pseudo-differential operators with self-tangential characteristics. 1987. Vol. 27. In Arkiv for Matematik. pp.65-88. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203528847912502.