Cita APA (7a ed.)

Cohen, D. 1. S. 2., Lee, T., & Sklar, D. (2006). Precalculus with unit-circle trigonometry (4th ed.). Thomson Brooks/Cole.

Cita Chicago Style (17a ed.)

Cohen, David 1942 September 28-, Theodore Lee, y David Sklar. Precalculus with Unit-circle Trigonometry. 4th ed. Belmont, CA: Thomson Brooks/Cole, 2006.

Cita MLA (9a ed.)

Cohen, David 1942 September 28-, et al. Precalculus with Unit-circle Trigonometry. 4th ed. Thomson Brooks/Cole, 2006.