@inproceedings{erik1984invariant,
title={Invariant differential operators on a semisimple symmetric space and finite multiplicities in a Plancherel formula},
author={Erik P. van den Ban},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203524195744463},
booktitle={Arkiv for Matematik},
volume={25},
number={1},
pages={175-187},
year={1984},
}
Erik P. van den Ban. Invariant differential operators on a semisimple symmetric space and finite multiplicities in a Plancherel formula. 1984. Vol. 25. In Arkiv for Matematik. pp.175-187. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203524195744463.