APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

Langley, Emile J., and Roger B. Knowles. Psychology of Sadness. New York: Novinka/Nova Science Publishers, Inc., 2012.

MLA (9th ed.) Citation

Langley, Emile J., and Roger B. Knowles. Psychology of Sadness. Novinka/Nova Science Publishers, Inc., 2012.