Sharp, H. J. (1953). Elements of plane trigonometry. Prentice-Hall.
Cita Chicago (17th ed.)Sharp, Henry Jr. Elements of Plane Trigonometry. Englewood Cliffs, New Jersey: Prentice-Hall, 1953.
Cita MLA (9th ed.)Sharp, Henry Jr. Elements of Plane Trigonometry. Prentice-Hall, 1953.
Atenció: Aquestes cites poden no estar 100% correctes.