Ali, F., F. Maiz, and El Sayed. Y. 2015. “Effect of UV Irradiation on the Structural and Optical Properties of Polymethylmethacrylate (PMMA) Doped With Chromium Nitrate”. Journal of Qassim University for Science 8 (1):1-13. https://jnsm.qu.edu.sa/index.php/jnm/article/view/1768.