TUME ATUA, T.; LATEEF DAHHAM, D.; SALIM MESR, I. The Role of Quality of Service as a Tool to Achieve Relationship Marketing. An Empirical Study of a Sample of Mobile Phone Company (Asiacell) Customers in Anbar Governorate. OpciĆ³n, v. 35, p. 1173-1198, 19 oct. 2019.