APA (7th ed.) Citation

Heiland, F. (1955). Merkur und Venus. Zeiss-Planetarium.

Chicago Style (17th ed.) Citation

Heiland, Fritz. Merkur Und Venus. Jena: Zeiss-Planetarium, 1955.

MLA (9th ed.) Citation

Heiland, Fritz. Merkur Und Venus. Zeiss-Planetarium, 1955.

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