@inproceedings{taksu2004an,
title={An approximation to couplings on graphs},
author={Taksu Cheon, and Pavel Exner},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191020123029696641578},
booktitle={Journal of Physics A: Mathematical and General},
volume={37},
number={29},
pages={L329},
year={2004},
}
Taksu Cheon, and Pavel Exner. An approximation to couplings on graphs. 2004. Vol. 37. In Journal of Physics A: Mathematical and General. pp.L329. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191020123029696641578.