@inproceedings{mogens1973the,
title={The convolution structure for Jacobi function expansions},
author={Mogens Flensted-Jensen, and Tom Koornwinder},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203452331369195},
booktitle={Arkiv for Matematik},
volume={11},
number={1},
pages={245-262},
year={1973},
}
Mogens Flensted-Jensen, and Tom Koornwinder. The convolution structure for Jacobi function expansions. 1973. Vol. 11. In Arkiv for Matematik. pp.245-262. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203452331369195.