APA (7th ed.) Citation

Asimov, I. (1981). Außerirdische Zivilisation.

Chicago Style (17th ed.) Citation

Asimov, Isaac. Außerirdische Zivilisation. 1981.

MLA (9th ed.) Citation

Asimov, Isaac. Außerirdische Zivilisation. 1981.

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