APA (7th ed.) Citation

Kröger, J., & Helwing, B. (2011). Friedrich Sarre.

Chicago Style (17th ed.) Citation

Kröger, Jens, and B. Helwing. Friedrich Sarre. 2011.

MLA (8th ed.) Citation

Kröger, Jens, and B. Helwing. Friedrich Sarre. 2011.

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