@unpublished{EgorovKondratievSchulze2004,
  author    = {Egorov, Jurij V. and Kondratiev, V. A. and Schulze, Bert-Wolfgang},
  title     = {On the completeness of root functions of elliptic boundary problems in a domain with conical points on the boundary},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26773},
  year      = {2004},
  abstract  = {Contents: 1 Introduction 2 Definitions 3 Rays of minimal growth 4 Proof of Theorem 2. 5 The growth of the resolvent 6 Proof of Theorem 3. 7 The completeness of root functions 8 Some generalizations},
  language  = {en}
}
@book{EgorovSchulze1997,
  author    = {Egorov, Jurij V. and Schulze, Bert-Wolfgang},
  title     = {Pseudo-differential operators, singularities, applicatons},
  series = {Operator theory},
  volume    = {93},
  journal   = {Operator theory},
  publisher = {Birkh{\"a}user},
  address   = {Basel},
  isbn      = {3-7643-5484-4},
  pages     = {XII; 349 S.},
  year      = {1997},
  language  = {en}
}