@inproceedings{birgit1978reducibility,
title={Reducibility of generalized principal series representations},
author={Birgit Speh, and David A. Vogan Jr},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203252972767286},
booktitle={Acta Mathematica},
volume={145},
number={1},
pages={227-299},
year={1978},
}
Birgit Speh, and David A. Vogan Jr. Reducibility of generalized principal series representations. 1978. Vol. 145. In Acta Mathematica. pp.227-299. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203252972767286.