Manna, Dean R., Gayle Marco, Denise Letterman, and Jesse Mullen. “Sustainable Case Study: Chevron Corporation”. Journal of Sustainability Management (JSM) 2, no. 1 (July 16, 2014): 31-34. Accessed August 18, 2020. https://clutejournals.com/index.php/JSM/article/view/8755.