APA (7th ed.) Citation

Penrose, L. S. (1966). The biology of mental defect (2. ed., 2. impr.). Sidgwick and Jackson.

Chicago Style (17th ed.) Citation

Penrose, Lionel S. The Biology of Mental Defect. 2. ed., 2. impr. London: Sidgwick and Jackson, 1966.

MLA (9th ed.) Citation

Penrose, Lionel S. The Biology of Mental Defect. 2. ed., 2. impr. Sidgwick and Jackson, 1966.