@article{WittkowskiLangerWeigelt1998,
  author    = {Wittkowski, M. and Langer, Norbert and Weigelt, G.},
  title     = {Diffraction-limited Speckle-Masking interferometry of the red supergiant VY CMa*},
  year      = {1998},
  language  = {en}
}
@article{OsterbartLangerWeigelt1997,
  author    = {Osterbart, R. and Langer, Norbert and Weigelt, G.},
  title     = {High-resolution imaging of the bipola Red Rectangle},
  year      = {1997},
  language  = {en}
}