@article{UBHD-67502064, author={Bien, Reinhold and J{\"a}hrling, Rainer and Wielen, Roland}, title={Astronomy for the public}, subtitle={the 'Astronomische Grundlagen f{\"u}r den Kalender'}, year={1990}, pages={55}, language={eng}, volume={5}, note={Gesehen am 25.11.2013}, journal={Abstract series}, } @incollection{UBHD-67497019, author={Wielen, Roland and Bernstein, Hans-Heinrich and Dettbarn, Christian and Hering, Roland and J{\"a}hrling, Rainer and Lenhardt, Helmut and Walter, Hans G.}, title={A test of preliminary HIPPARCOS parallaxes using photometric parallaxes of distant stars}, year={1994}, pages={74-79}, language={eng}, isbn={0-521-46240-1 and 978-0-521-46240-2}, booktitle={Galactic and solar system optical astrometry}, editor={Morrison, L. V.}, }