@inproceedings{g.1914some,
title={Some problems of diophantine approximation},
author={G. H. Hardy, and J. E. Littlewood},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203028023101242},
booktitle={Acta Mathematica},
volume={37},
number={1},
pages={155-191},
year={1914},
}