APA (7th ed.) Citation

Spencer, H. (1885). The principles of psychology. D. Appleton.

Chicago Style (17th ed.) Citation

Spencer, Herbert. The Principles of Psychology. New York: D. Appleton, 1885.

MLA (9th ed.) Citation

Spencer, Herbert. The Principles of Psychology. D. Appleton, 1885.

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