E. A. Tawfiq and G. M. Kamil, “Modification of Spectral Properties of Polystyrene / Diethyl phthalate in Different Solutions”, Iraqi Journal of Science, vol. 60, no. 4, pp. 762–768, May 2019, Accessed: Dec. 18, 2025. [Online]. Available: https://www.ijs.uobaghdad.edu.iq/index.php/eijs/article/view/755