@inproceedings{j.1962lipschitz,
title={Lipschitz approximations to summable functions},
author={J. H. Michael},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203203386525971},
booktitle={Acta Mathematica},
volume={111},
number={1},
pages={73-95},
year={1962},
}