@article{UBHD-67928336,
  author={Bloom, Steven D. and Bock, Holger Arne and Dietrich, Matthias and Otterbein, Kai and Wagner, Stefan},
  title={Observations of a correlated gamma-ray and optical flare for BL Lacertae},
  year={1997},
  pages={L145-L148},
  language={eng},
  issn={2041-8213},
  volume={490},
  number={2},
  note={Gesehen am 21.01.2016},
  journal={The astrophysical journal},
  doi={10.1086/311035},
}
@article{UBHD-67931687,
  author={Otterbein, Kai and Wagner, Stefan},
  title={Gamma-ray to radio activity and ejection of a VLBI component in the jet of the S5-quasar 0836+J.710},
  year={1998},
  pages={489-497},
  language={eng},
  issn={1432-0746},
  volume={334},
  note={Gesehen am 28.01.2016},
  journal={Astronomy and astrophysics},
}
@conference{UBHD-68021259,
  author={Otterbein, Kai and Wagner, Stefan},
  title={The ROSAT field around the intraday variable quasar 0917+62},
  year={1994},
  pages={589},
  language={eng},
  isbn={4-946443-22-3 and 978-4-946443-22-0},
}