Lefton, L. A., & Valvatne, L. (1986). Mastering Psychology (2nd ed.). Allyn & Bacon.
Cita Chicago (17th ed.)Lefton, Lester A., i Laura Valvatne. Mastering Psychology. 2nd ed. Boston: Allyn & Bacon, 1986.
Cita MLA (9th ed.)Lefton, Lester A., i Laura Valvatne. Mastering Psychology. 2nd ed. Allyn & Bacon, 1986.
Atenció: Aquestes cites poden no estar 100% correctes.