@inproceedings{taksu2010approximation,
title={Approximation of a general singular vertex coupling in quantum graphs},
author={Taksu Cheon, Pavel Exner, and Ondej Turek},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191020122935786707575},
booktitle={Annals of Physics},
volume={325},
number={3},
pages={548-578},
year={2010},
}
Taksu Cheon, Pavel Exner, and Ondej Turek. Approximation of a general singular vertex coupling in quantum graphs. 2010. Vol. 325. In Annals of Physics. pp.548-578. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191020122935786707575.