@inproceedings{robert1938linear,
title={Linear differential equations with almost periodic coefficients},
author={Robert H. Cameron},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203111784935587},
booktitle={Acta Mathematica},
volume={69},
number={1},
pages={21-56},
year={1938},
}
Robert H. Cameron. Linear differential equations with almost periodic coefficients. 1938. Vol. 69. In Acta Mathematica. pp.21-56. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203111784935587.