@inproceedings{d.1993invariant,
title={Invariant subspaces in Bergman spaces and Hedenmalm's boundary value problem},
author={D. Khavinson, and H. S. Shapiro},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203543668264627},
booktitle={Arkiv for Matematik},
volume={32},
number={2},
pages={309-321},
year={1993},
}

D. Khavinson, and H. S. Shapiro. Invariant subspaces in Bergman spaces and Hedenmalm's boundary value problem. 1993. Vol. 32. In Arkiv for Matematik. pp.309-321. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203543668264627.