APA (7th ed.) Citation

Drooyan, I., Hadel, W., & Carico, C. C. (1977). Essentials of trigonometry (2d ed.). Macmillan.

Chicago Style (17th ed.) Citation

Drooyan, Irving, Walter Hadel, and Charles C. Carico. Essentials of Trigonometry. 2d ed. New York: Macmillan, 1977.

MLA (9th ed.) Citation

Drooyan, Irving, et al. Essentials of Trigonometry. 2d ed. Macmillan, 1977.