APA (7th ed.) Citation

Helbling, R. E., Gewehr, W., & Von Schmidt, W. A. (1975). First-year German. Holt, Rinehart and Winston.

Chicago Style (17th ed.) Citation

Helbling, Robert E., Wolf Gewehr, and Wolff A. Von Schmidt. First-year German. New York: Holt, Rinehart and Winston, 1975.

MLA (9th ed.) Citation

Helbling, Robert E., et al. First-year German. Holt, Rinehart and Winston, 1975.