Alhakam, Iptehaj, and Nassir H Salman. “An Improved Probability Density Function (PDF) for Face Skin Detection”. Iraqi Journal of Science 63, no. 10 (October 30, 2022): 4460–4473. Accessed January 5, 2026. https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/2691.