Opilo, P. M., D. B. Mulili, and D. S. Kimani. “Corporate Social Responsibility and Competitive Advantage Perspectives from Employees of Safaricom Kenya Limited”. Journal of Marketing and Communication, vol. 1, no. 2, Aug. 2018, pp. 1-21, https://stratfordjournals.org/journals/index.php/journal-of-marketing/article/view/163.