Authors
Heinz Andernach
Argelander-Institut für Astronomie, Universität Bonn D-53121 Bonn, Germany (on leave of absence from Depto. de Astronomía, Universidad de Guanajuato, Mexico)

© 2009 Heinz Andernach, published by Ubiquity Press
This work is licensed under the Creative Commons Attribution 4.0 License.