APA (7th ed.) Citation

Skemp, R. R. (1986). The psychology of learning mathematics (2nd ed.). Penguin.

Chicago Style (17th ed.) Citation

Skemp, Richard R. The Psychology of Learning Mathematics. 2nd ed. [Harmonsworth, Essex]: Penguin, 1986.

MLA (9th ed.) Citation

Skemp, Richard R. The Psychology of Learning Mathematics. 2nd ed. Penguin, 1986.