Citazione Stile APA (7a Edizione)

Spencer, H. (1970). The principles of psychology. Gregg International Publishers Limited.

Citazione stile Chigago Style (17a edizione)

Spencer, Herbert. The Principles of Psychology. Farnham: Gregg International Publishers Limited, 1970.

Citatione MLA (9a ed.)

Spencer, Herbert. The Principles of Psychology. Gregg International Publishers Limited, 1970.