References for "In praise of gratitude"
Emmons RA, et al. "Counting Blessings Versus Burdens: An Experimental Investigation of Gratitude and Subjective Well-Being in Daily Life," Journal of Personality and Social Psychology (Feb. 2003): Vol. 84, No. 2, pp. 377–89.
Grant AM, et al. "A Little Thanks Goes a Long Way: Explaining Why Gratitude Expressions Motivate Prosocial Behavior," Journal of Personality and Social Psychology (June 2010): Vol. 98, No. 6, pp. 946–55.
Lambert NM, et al. "Expressing Gratitude to a Partner Leads to More Relationship Maintenance Behavior," Emotion (Feb. 2011): Vol. 11, No. 1, pp. 52–60.