Emmons, R. A. (2007). Thanks!: How the new science of gratitude can make you happier. Houghton Mifflin Co..
Cita Chicago Style (17a ed.)Emmons, Robert A. Thanks!: How the New Science of Gratitude Can Make You Happier. Boston, Mass.: Houghton Mifflin Co., 2007.
Cita MLA (8a ed.)Emmons, Robert A. Thanks!: How the New Science of Gratitude Can Make You Happier. Houghton Mifflin Co., 2007.
Precaución: Estas citas no son 100% exactas.