@inproceedings{rupert2004on,
title={On the Laplacian in the halfspace with a periodic boundary condition},
author={Rupert L. Frank},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203617103718890},
booktitle={Arkiv for Matematik},
volume={44},
number={2},
pages={277-298},
year={2004},
}
Rupert L. Frank. On the Laplacian in the halfspace with a periodic boundary condition. 2004. Vol. 44. In Arkiv for Matematik. pp.277-298. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203617103718890.