APA (7th ed.) Citation

Nagel, A., & Helwing, B. (2011). Ernst E. Herzfeld.

Chicago Style (17th ed.) Citation

Nagel, Alexander, and B. Helwing. Ernst E. Herzfeld. 2011.

MLA (8th ed.) Citation

Nagel, Alexander, and B. Helwing. Ernst E. Herzfeld. 2011.

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