Mutar, Mohammed A., and Rafid K. Kmal. 2017. “Preparation of Copolymer of Acrylamide and Acrylic Acid and Its Application for Slow Release Sodium Nitrate Fertilizer”. Al-Qadisiyah Journal of Pure Science 17 (4), 71-83. https://journalsc.qu.edu.iq/index.php/JOPS/article/view/483.