Cohen, D. (1994). Precalculus with unit-circle trigonometry (2nd ed.). West Publishing Company.
芝加哥风格引文Cohen, David. Precalculus with Unit-circle Trigonometry. 2nd ed. Minneapolis, NY: West Publishing Company, 1994.
MLA引文Cohen, David. Precalculus with Unit-circle Trigonometry. 2nd ed. West Publishing Company, 1994.
警告：这些引文格式不一定是100％准确.