@article{DP13,
  title = "Automorphisms of necklaces and sandpile groups",
  author = "S. Duzhin and D.V. Pasechnik",
  year = "2014",
  journal = "Notes of Scientific Seminars of the St.Petersburg Department of the Steklov Mathematical Institute",
  note = "arXiv.org e-print 1304.2563",
  pages = "81--93",
  url = "ftp://ftp.pdmi.ras.ru/pub/publicat/znsl/v421/p081.pdf",
  volume = "421",
}