A. Mutar, Mohammed, and Sabrean F. Jawad. 2018. “Synthesis And Characterization Of New Type Of Biodegradable Polyurethane Containing Azo Derivatives Of Benzocaine”. Al-Qadisiyah Journal of Pure Science 20 (3), 110 -38. https://journalsc.qu.edu.iq/index.php/JOPS/article/view/841.