Wogu, Onyekachi E., and Michael D. Oisamoje. “Customer Service Quality Perception and Expectation of GSM Companies in Benin City, Nigeria”. The International Journal of Business & Management 4, no. 2 (February 27, 2015). Accessed May 17, 2024. http://www.internationaljournalcorner.com/index.php/theijbm/article/view/126229.