Cita APA (7th ed.)

ZILL, D. G., & DEWAR, J. M. (1990). Trigonometry.-- Ed.2. McGraw-Hill.

Cita Chicago (17th ed.)

ZILL, Dennis G., i Jacqueline M. DEWAR. Trigonometry.-- Ed.2. New York: McGraw-Hill, 1990.

Cita MLA (9th ed.)

ZILL, Dennis G., i Jacqueline M. DEWAR. Trigonometry.-- Ed.2. McGraw-Hill, 1990.