@inproceedings{g.1930a,
title={A maximal theorem with function-theoretic applications},
author={G. H. Hardy, and J. E. Littlewood},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203053647892446},
booktitle={Acta Mathematica},
volume={54},
number={1},
pages={81-116},
year={1930},
}
G. H. Hardy, and J. E. Littlewood. A maximal theorem with function-theoretic applications. 1930. Vol. 54. In Acta Mathematica. pp.81-116. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203053647892446.