Ihsan ullah, J. Awan, Fatima Gillani, and Iqra Shahzad. “Role of Agile Methodologies for Ensuring Quality in Complex Systems: A Systematic Literature Review”. International Journal of Innovations in Science & Technology, vol. 4, no. 4, Nov. 2022, pp. 1042-54, https://journal.50sea.com/index.php/IJIST/article/view/391.