BHUTTO, R. A.; MAQSOOD, A. Customer Services: A Case Study of Cellular Phone Companies in Pakistan . JISR management and social sciences & economics, [S. l.], v. 5, n. 1, p. 19–23, 2007. Disponível em: https://jisrmsse.szabist.edu.pk/index.php/szabist/article/view/366. Acesso em: 11 may. 2024.