APA (7th ed.) Citation

Klaus, G. (1968). Was ist - was soll. Urania-Verlag.

Chicago Style (17th ed.) Citation

Klaus, Georg. Was Ist - Was Soll. Leipzig: Urania-Verlag, 1968.

MLA (8th ed.) Citation

Klaus, Georg. Was Ist - Was Soll. Urania-Verlag, 1968.

Warning: These citations may not always be 100% accurate.