@article{BrascheNeidhardt1995,
  author    = {Brasche, Johannes F. and Neidhardt, Hagen},
  title     = {On the point spectrum of selfadjoint extensions},
  year      = {1995},
  language  = {en}
}
@article{BrascheNeidhardt1996,
  author    = {Brasche, Johannes F. and Neidhardt, Hagen},
  title     = {On the singular continuous spectrum of self-adjoint extensions},
  year      = {1996},
  language  = {en}
}
@article{BrascheNeidhardt1995,
  author    = {Brasche, Johannes F. and Neidhardt, Hagen},
  title     = {On the absolutely continuous spectrum of self-adjoint extensions},
  year      = {1995},
  language  = {en}
}
@article{AlbeverioBrascheNeidhardt1998,
  author    = {Albeverio, Sergio and Brasche, Johannes F. and Neidhardt, Hagen},
  title     = {On inverse spectral theory: mixed types of spectra.},
  year      = {1998},
  language  = {en}
}
@article{BrascheNeidhardt1994,
  author    = {Brasche, Johannes F. and Neidhardt, Hagen},
  title     = {Some remarks to Krein's extension theory},
  year      = {1994},
  language  = {en}
}
@article{BrascheKoshmanenkoNeidhardt1994,
  author    = {Brasche, Johannes F. and Koshmanenko, V. D. and Neidhardt, Hagen},
  title     = {Some new aspects of Krein's extension theory},
  year      = {1994},
  language  = {en}
}