@unpublished{ChenYu2001,
  author    = {Chen, Hua and Yu, Chun},
  title     = {Asymptotic behaviour of the trace for Schr{\"o}dinger operator on fractal drums},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26157},
  year      = {2001},
  language  = {en}
}