@book{UBHD-65171806,
  author={Becken, Wolfgang},
  title={Elektronische Struktur des Helium-Atoms im starken Magnetfeld},
  year={2000},
  pages={304 S.},
  language={ger},
  school={Heidelberg, Univ., Diss., 2000},
  library={UB [Signatur: 2001 U 73]},
}
@article{UBHD-68023480,
  author={Jordan, Stefan and Becken, Wolfgang},
  title={Evidence for helium in the magnetic white dwarf GD 229},
  year={1998},
  pages={L33-L36},
  language={eng},
  issn={1432-0746},
  volume={336},
  note={Gesehen am 31.08.2016},
  journal={Astronomy and astrophysics},
}
@article{UBHD-68023455,
  author={Jordan, Stefan and Schmelcher, Peter and Becken, Wolfgang},
  title={Stationary components of He I in strong magnetic fields},
  subtitle={a tool to identify magnetic DB white dwarfs},
  year={2001},
  pages={614-620},
  language={eng},
  issn={1432-0746},
  volume={376},
  number={2},
  note={Gesehen am 31.08.2016},
  journal={Astronomy and astrophysics},
  doi={10.1051/0004-6361:20010970},
}