@inproceedings{a.1950hypergeometric,
title={Hypergeometric functions of two variables},
author={A. Erdélyi},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203128296312711},
booktitle={Acta Mathematica},
volume={83},
number={1},
pages={131-164},
year={1950},
}

A. Erdélyi. Hypergeometric functions of two variables. 1950. Vol. 83. In Acta Mathematica. pp.131-164. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203128296312711.