APA (7th ed.) Zitazioa

ebrary, Inc, Langley, E. J., & Knowles, R. B. (2012). Psychology of sadness. Nova Science Publishers.

Chicago Style (17th ed.) Zitazioa

ebrary, Inc, Emile J. Langley, eta Roger B. Knowles. Psychology of Sadness. New York: Nova Science Publishers, 2012.

MLA (9th ed.) Zitazioa

ebrary, Inc, et al. Psychology of Sadness. Nova Science Publishers, 2012.