@inproceedings{fritz2015a,
title={A bound for the eigenvalue counting function for higher-order Krein Laplacians on open sets},
author={Fritz Gesztesy, Pavel Exner, S Sukhtaiev, and A Laptev},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191020133705131784748},
pages={3-29},
year={2015},
}
Fritz Gesztesy, Pavel Exner, S Sukhtaiev, and A Laptev. A bound for the eigenvalue counting function for higher-order Krein Laplacians on open sets. 2015. pp.3-29. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191020133705131784748.