Yahya, W. K. (2003). Customer service: Why it is so poor and how to improve it / Wan Kalthom Yahya.
Chicago Style (17. basım) AtıfYahya, Wan Kalthom. Customer Service: Why It Is so Poor and How to Improve It / Wan Kalthom Yahya. 2003.
MLA (9th ed.) AtıfYahya, Wan Kalthom. Customer Service: Why It Is so Poor and How to Improve It / Wan Kalthom Yahya. 2003.
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