Proudfoot, A. (1960). Practical trigonometry. Macmillian & Co. Ltd.
Cita Chicago (17th ed.)Proudfoot, A. Practical Trigonometry. London: Macmillian & Co. Ltd, 1960.
Cita MLA (9th ed.)Proudfoot, A. Practical Trigonometry. Macmillian & Co. Ltd, 1960.
Atenció: Aquestes cites poden no estar 100% correctes.