6Emmons Ik, Crumpler C: Gratitude as a human strength: Appraising the evidence. Journal of Social and Clinical Psychology 2000, 19(1):56-69.
7McCultough ME, Emmons RA, Tsang JA: The grateful disposition: A conceptual and empirical topography. Journal of Personality and Social Psychology 2002, 82(1):112-127.
8Emmons RA, McCullough ME: Counting blessings versus burdens: An experimental investigation of gratitude and subjective well-being in daily life. Journal of Personality and Social Psychology 2003, 84(2):377-389.
9Linley P, Maltby J, Wood A, Osborne G, Hurling R: Measuring happiness: The higher order factor structure of subjective and psychological well-being measures. Personality and Individual Differences 2009, 47(8):878-884.
10McCullough M, Kilpatrick S, Emmons R, Larson D: Is gratitude a moral affect? Psychological Bulletin 2001, 127(2):249-266.
