@unpublished{EgorovKondratievSchulze2001,
  author    = {Egorov, Yu. and Kondratiev, V. and Schulze, Bert-Wolfgang},
  title     = {On completeness of eigenfunctions of an elliptic operator on a manifold with conical points},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25937},
  year      = {2001},
  abstract  = {Contents: 1 Introduction 2 Definitions 3 Rays of minimal growth 4 Completeness of root functions},
  language  = {en}
}