H. Hashim, M. Abdallh, and E. Yousif, “Studying the Influence of Cobalt Chloride on the Optical Properties of Poly (vinyl alcohol) Films”, Al-Nahrain J. Sci., vol. 15, no. 1, pp. 40–45, Sep. 2018, Accessed: May 22, 2026. [Online]. Available: https://mail.anjs.edu.iq/index.php/anjs/article/view/1543