APA (7th ed.) Citation

Horn, R. (1989). An American Problem. Urania-Verlag.

Chicago Style (17th ed.) Citation

Horn, Rüdiger. An American Problem. Leipzig - Jena - Berlin: Urania-Verlag, 1989.

MLA (8th ed.) Citation

Horn, Rüdiger. An American Problem. Urania-Verlag, 1989.