Ekers, Michael, and Charles Z. Levoke. “Transformations in Agricultural Non-Waged Work: From Kinship to Intern and Volunteer Labor: A Research Brief”. Journal of Agriculture, Food Systems, and Community Development 6, no. 2 (February 11, 2016): 179-183. Accessed September 18, 2019. https://foodsystemsjournal.org/index.php/fsj/article/view/455.