APA (7th ed.) Citation

O' Neil, W. (1968). The beginnings of modern psychology. Penguin Books.

Chicago Style (17th ed.) Citation

O' Neil, W.M. The Beginnings of Modern Psychology. Middlesex: Penguin Books, 1968.

MLA (9th ed.) Citation

O' Neil, W.M. The Beginnings of Modern Psychology. Penguin Books, 1968.

Warning: These citations may not always be 100% accurate.