APA (7th ed.) Citation

Spencer, H. (1896). The principles of psychology. Appleton.

Chicago Style (17th ed.) Citation

Spencer, Herbert. The Principles of Psychology. New York: Appleton, 1896.

MLA (9th ed.) Citation

Spencer, Herbert. The Principles of Psychology. Appleton, 1896.

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