Cita APA

Emmons, R. A., & McCullough, M. E. (2004). The psychology of gratitude. Oxford: Oxford University Press.

Citación estilo Chicago

Emmons, Robert A., y Michael E. McCullough. The Psychology of Gratitude. Oxford: Oxford University Press, 2004.

Cita MLA

Emmons, Robert A., y Michael E. McCullough. The Psychology of Gratitude. Oxford: Oxford University Press, 2004.