Cita APA (7th ed.)
Roethel, L. F. (1965). To improve your grades in trigonometry (1a. ed.). Collier Books.
Cita Chicago (17th ed.)
Roethel, Louis F. To Improve Your Grades in Trigonometry. 1a. ed. New York: Collier Books, 1965.
Cita MLA (9th ed.)
Roethel, Louis F. To Improve Your Grades in Trigonometry. 1a. ed. Collier Books, 1965.
Atenció: Aquestes cites poden no estar 100% correctes.