Mgiba, Freddy Marilahimbilu. “Social Network Theory, Sigma Six, and Customer Experience Management: Common Elements That Aid Positive Sales-Marketing Interface: A Review of the Literature”. International Review of Management and Marketing, vol. 9, no. 5, Sept. 2019, pp. 165-72, https://mail.econjournals.com/index.php/irmm/article/view/8674.