Astrophysiker Stephen Hawking, Carl Sagan, Karl Schwarzschild, Hannes Alfvén, Jürgen Ehlers, Harald Lesch, Thomas Gold, Walter Baade, Jacques Vallée, Erich Jantsch, Hans-Jürgen Treder, Josef Allen Hynek, David Brin, Milutin Milankovic, Joachim Trümper by Quelle Wikipedia , Bucher Gruppe , Bcher Gruppe Paperback, 94 Pages, Published 2011 by Books Llc, Wiki Series ISBN-13: 978-1-158-79357-0, ISBN: 1-158-79357-X