@inproceedings{pavel2017cantor,
title={Cantor spectra of magnetic chain graphs},
author={Pavel Exner, and Daniel Vaata},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191020134538207342773},
booktitle={Journal of Physics A: Mathematical and Theoretical},
volume={50},
number={16},
pages={165201},
year={2017},
}

Pavel Exner, and Daniel Vaata. Cantor spectra of magnetic chain graphs. 2017. Vol. 50. In Journal of Physics A: Mathematical and Theoretical. pp.165201. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191020134538207342773.