APA (7th ed.) Citation

Helrich, C. S. (1999). Thermodynamics: What one needs to know. Zygon, 34(3), 501-514.

Chicago Style (17th ed.) Citation

Helrich, Carl S. "Thermodynamics: What One Needs to Know." Zygon 34, no. 3 (1999): 501-514.

MLA (8th ed.) Citation

Helrich, Carl S. "Thermodynamics: What One Needs to Know." Zygon, vol. 34, no. 3, 1999, pp. 501-514.