APA (7th ed.) Citation

Servais, W., & Varga, T. (1971). Teaching school mathematics. Penguin Books.

Chicago Style (17th ed.) Citation

Servais, W., and T. Varga. Teaching School Mathematics. Harmondsworth: Penguin Books, 1971.

MLA (9th ed.) Citation

Servais, W., and T. Varga. Teaching School Mathematics. Penguin Books, 1971.