APA (7th ed.) Citation

Petersen, K., & Feddersen, E. (1969). Trigonometrie. Schroedel.

Chicago Style (17th ed.) Citation

Petersen, Karla, and Elise Feddersen. Trigonometrie. Hannover [u.a.]: Schroedel, 1969.

MLA (9th ed.) Citation

Petersen, Karla, and Elise Feddersen. Trigonometrie. Schroedel, 1969.

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