Su, M. T., T. C. Ling, K. K. Phang, C. S. Liew, and P. Y. Man. “Enhanced Software Development Effort and Cost Estimation Using Fuzzy Logic Model”. Malaysian Journal of Computer Science, vol. 20, no. 2, Dec. 2007, pp. 199-07, https://juku.um.edu.my/index.php/MJCS/article/view/6308.