APA (7th ed.) Citation

Westermann, H. C., Barrette, B., & Westermann, J. B. (1988). Letters from H.C. Westermann. Timken Publishers.

Chicago Style (17th ed.) Citation

Westermann, H. C., Bill Barrette, and Joanna Beall Westermann. Letters from H.C. Westermann. New York: Timken Publishers, 1988.

MLA (9th ed.) Citation

Westermann, H. C., et al. Letters from H.C. Westermann. Timken Publishers, 1988.