@inproceedings{l.1939the,
title={The method of successive approximation for functional equations},
author={L. Kantorovitch},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203114237228603},
booktitle={Acta Mathematica},
volume={71},
number={1},
pages={63-97},
year={1939},
}