S. Q. Park et al., “A Neural Link between Generosity and Happiness,” Nature Communications 8 (2017): 159674, doi: 10.1038/ncomms15964; S. G. Post, “Altruism, Happiness, and Health: It’s Good to Be Good,” International Journal of Behavioral Medicine 12, no. 2 (2005): 66–77, doi: 10.1207/s15327558ijbm1202_4; L. B. Aknin et al., “Giving Leads to Happiness in Young Children,” PLOS ONE 7, no. 6 (2012): e39211, doi: 10.1371 / journal.pone.0039211.
