The representative in Great Britain of the Freedom Station [d. i. Jürgen Kuczynski]: Freedom calling! The story of the secret German radio. 1. Aufl., London: Frederick Muller Ltd. 1939, 64 S.
The representative in Great Britain of the Freedom Station [d. i. Jürgen Kuczynski]: Freedom calling! The story of the secret German radio. 2. Aufl., London: Frederick Muller Ltd. 1939, 64 S.
The representative in Great Britain of the Freedom Station [d. i. Jürgen Kuczynski]: Freedom calling! The story of the secret German radio. 3. Aufl., London: Frederick Muller Ltd. 1940, 64 S.