Tanik, Abdulsamet, and Mehmet Gül. “The Validity of the Community Periodontal Index of Treatment Needs (CPITN) in Epidemiological Studies of Periodontal Diseases”. International Dental Research 10, no. 2 (August 31, 2020): 44-48. Accessed March 4, 2021. https://www.dental-research.com/index.php/idr/article/view/206.