Ahmed , Z. A. ., Q. H. . Ubaid, and M. A. . Al-Kaabi. “Investigation The Non Linear Optical Properties and Spectroscopy Properties of Polyimide Using DFT”. Journal of Neonatal Surgery, vol. 14, no. 21S, May 2025, pp. 128-35, https://www.jneonatalsurg.com/index.php/jns/article/view/5235.