APA (7th ed.) Citation

Gathercole, C. E. (1968). Assessment in clinical psychology. Penguin Books.

Chicago Style (17th ed.) Citation

Gathercole, C. E. Assessment in Clinical Psychology. Harmondsworth ; Baltimore: Penguin Books, 1968.

MLA (9th ed.) Citation

Gathercole, C. E. Assessment in Clinical Psychology. Penguin Books, 1968.