@inproceedings{l.1958solution,
title={Solution of a mixed problem for a hyperbolic differential equation by Riemann's method},
author={L. Lorne Campbell},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203148755814862},
booktitle={Acta Mathematica},
volume={100},
number={1},
pages={23-43},
year={1958},
}
L. Lorne Campbell. Solution of a mixed problem for a hyperbolic differential equation by Riemann's method. 1958. Vol. 100. In Acta Mathematica. pp.23-43. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203148755814862.