@inproceedings{luigi1974on,
title={On the$L$^{$2$}continuity of a class of pseudo differential operators},
author={Luigi Rodino},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203458291885246},
booktitle={Arkiv for Matematik},
volume={14},
number={1},
pages={141-153},
year={1974},
}
Luigi Rodino. On the$L$^{$2$}continuity of a class of pseudo differential operators. 1974. Vol. 14. In Arkiv for Matematik. pp.141-153. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203458291885246.