Farrelly, Daniel, Emma Moan, Kristi White, and Sarah Young. “Evidence of an Alternative Currency for Altruism in Laboratory-Based Experiments”. Europe’s Journal of Psychology 11, no. 1 (February 27, 2015): 100-111. Accessed September 25, 2022. https://ejop.psychopen.eu/index.php/ejop/article/view/855.