@inproceedings{pavel2006necklaces,
title={Necklaces with interacting beads: isoperimetric problems},
author={Pavel Exner},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191020130602944419649},
booktitle={Contemporary Mathematics},
volume={412},
pages={141-150},
year={2006},
}