Sadia Musharraf, et al. “KNOWLEDGE OF MEDICAL DOCTORS IN TWIN CITIES OF PAKISTAN ABOUT THE RELATIONSHIP BETWEEN PERIODONTAL DISEASE AND SYSTEMIC HEALTH”. Pakistan Oral & Dental Journal, vol. 41, no. 4, Dec. 2021, pp. 232-6, https://www.podj.com.pk/index.php/podj/article/view/659.