@inproceedings{percy2000perturbation,
title={Perturbation theory for infinite-dimensional integrable systems on the line. A case study},
author={Percy Deift, and Xin Zhou},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203340188142623},
booktitle={Acta Mathematica},
volume={188},
number={2},
pages={163-262},
year={2000},
}
Percy Deift, and Xin Zhou. Perturbation theory for infinite-dimensional integrable systems on the line. A case study. 2000. Vol. 188. In Acta Mathematica. pp.163-262. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203340188142623.