Samir Bhaya, Eman, and Malik Saad Al-Muhja. “On Monotone Approximation by Piecewise Positive Functions”. Journal of Al-Qadisiyah for Computer Science and Mathematics 3, no. 2 (October 1, 2017): 166–173. Accessed April 3, 2025. https://jqcsm.qu.edu.iq/index.php/journalcm/article/view/286.