@inproceedings{lars1970fourier,
title={Fourier integral operators. I},
author={Lars Hörmander},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203223219500118},
booktitle={Acta Mathematica},
volume={127},
number={1},
pages={79-183},
year={1970},
}