Theorien — was, wo, wie und warum?
From Author Wars - https://authorwars.com/books/theorien----was-wo-wie-und-warum-2377593.html
Editions/Publications:
- 1969 . Das Rätsel der UFOs (1969, various, Moewig, DM 2.40, 144 pages, Paperback, Non-fiction)
From Author Wars - https://authorwars.com/books/theorien----was-wo-wie-und-warum-2377593.html