APA (7th ed.) Citation

Richards, B. W., & Penrose, L. S. (1970). Mental subnormality: Modern trends in research. Pitman Medical & Scientific Publishing.

Chicago Style (17th ed.) Citation

Richards, B. W., and L. S. Penrose. Mental Subnormality: Modern Trends in Research. London: Pitman Medical & Scientific Publishing, 1970.

MLA (8th ed.) Citation

Richards, B. W., and L. S. Penrose. Mental Subnormality: Modern Trends in Research. Pitman Medical & Scientific Publishing, 1970.