APA (7th ed.) Citation

International Correspondence Schools. Plane trigonometry (2nd ed.). International Buildings.

Chicago Style (17th ed.) Citation

International Correspondence Schools. Plane Trigonometry. 2nd ed. London: International Buildings.

MLA (8th ed.) Citation

International Correspondence Schools. Plane Trigonometry. 2nd ed. International Buildings.

Warning: These citations may not always be 100% accurate.