APA (7th ed.) Citation

Ahnert, P. (1980). Kalender für Sternfreunde 1981. Johann Ambrosius Barth.

Chicago Style (17th ed.) Citation

Ahnert, Paul. Kalender Für Sternfreunde 1981. Leipzig: Johann Ambrosius Barth, 1980.

MLA (8th ed.) Citation

Ahnert, Paul. Kalender Für Sternfreunde 1981. Johann Ambrosius Barth, 1980.

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