1.  Robert A. Emmons and Michael E. McCullough, “Counting Blessings versus Burdens: An Experimental Investigation of Gratitude and Subject Well-Being in Daily Life,” Journal of Personality and Social Psychology 84.2 (February 2003): 377–89, https://greatergood.berkeley.edu/pdfs/GratitudePDFs/6Emmons-BlessingsBurdens.pdf (accessed July 6, 2017).