Παραπομπή σε μορφή APA (7η εκδ.)

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

Παραπομπή σε μορφή Chicago (17η εκδ.)

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

Παραπομπή σε μορφή MLA (8th εκδ.)

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