Rutledge, W. A., & Pond, J. A. (1961). Modern Trigonometry (2d ed.). Prentice-Hall.
Cita Chicago (17th ed.)Rutledge, William A., i John A. Pond. Modern Trigonometry. 2d ed. Englewood Cliffs, N.J: Prentice-Hall, 1961.
Cita MLA (9th ed.)Rutledge, William A., i John A. Pond. Modern Trigonometry. 2d ed. Prentice-Hall, 1961.
Atenció: Aquestes cites poden no estar 100% correctes.