@article{JonasLanger1993,
  author    = {Jonas, Peter and Langer, Heinz},
  title     = {Selfadjoint extensions of a closed linear relation of defect one in a Krein space},
  year      = {1993},
  language  = {en}
}
@book{JonasLanger1994,
  author    = {Jonas, Peter and Langer, Heinz},
  title     = {Selfadjoint extensions of a closed linear realtion of defect one in a Krein space. Universit{\"a}t Potsdam, Fachbereich Mathematik},
  series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik},
  volume    = {1994, 17},
  journal   = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik},
  publisher = {Univ.},
  address   = {Potsdam},
  pages     = {35 Bl.},
  year      = {1994},
  language  = {de}
}