@inproceedings{fan1996upper,
title={Upper bounds for eigenvalues of the discrete and continuous Laplace operators},
author={Fan RK Chung, A Grigor'Yan, and Shing-Tung Yau},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191224203819297966089},
booktitle={advances in mathematics},
volume={117},
number={2},
pages={165-178},
year={1996},
}

Fan RK Chung, A Grigor'Yan, and Shing-Tung Yau. Upper bounds for eigenvalues of the discrete and continuous Laplace operators. 1996. Vol. 117. In advances in mathematics. pp.165-178. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191224203819297966089.