Ibrahem, Dr. Lekaa M. “The Association Between a Marker of Oxidative Stress in Saliva and Severity of Periodontal Disease”. Mustansiria Dental Journal 4, no. 1 (April 4, 2018): 56–60. Accessed May 6, 2024. https://mdj.uomustansiriyah.edu.iq/index.php/mdj/article/view/584.