@inproceedings{hjalmar1883eine,
title={Eine Verallgemeinerung der Gleichung $$\Gamma (I + x)\Gamma (I - x) = \frac{{\pi x}}{{\sin \pi x}}.$$ },
author={Hjalmar Mellin},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108202930876165754},
booktitle={Acta Mathematica},
volume={3},
number={1},
pages={102-104},
year={1883},
}
Hjalmar Mellin. Eine Verallgemeinerung der Gleichung $$\Gamma (I + x)\Gamma (I - x) = \frac{{\pi x}}{{\sin \pi x}}.$$ . 1883. Vol. 3. In Acta Mathematica. pp.102-104. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108202930876165754.