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.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.