@inproceedings{reese1969removable,
title={Removable singularities of solutions of linear partial differential equations},
author={Reese Harvey, and John Polking},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203220916459102},
booktitle={Acta Mathematica},
volume={125},
number={1},
pages={39-56},
year={1969},
}
Reese Harvey, and John Polking. Removable singularities of solutions of linear partial differential equations. 1969. Vol. 125. In Acta Mathematica. pp.39-56. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203220916459102.