Gaya APA

Leod, R, H., H., I, S, C. (NULL). Precalculus algebra, trigonometry, and geometry . New: New York: Macmillan; 1981.

Gaya MLA

Leod, Roy, H.., H., I., Stolze,, Charles. "Precalculus algebra, trigonometry, and geometry". New: New York: Macmillan; 1981, NULL. Text.