1. Garcia, R. and Dietrich, T., Introduction to Periodontal Epidemiology, Periodontology, 2000, vol. 58, p. 7.
2. Academy Report “Epidemiology of Periodontal Diseases,” J. Periodontol., 2005, vol. 76, no. 8, p. 1406.
3. Dedova, L.N., Kandrukevich, O.V., and Bondarik, E.A., The State of Periodontal Tissue and Root Surface Caries According to the Epidemiological Survey 35 to 54 Year Old Residents of the Republic of Belarus, Stomatol. Zh., 2006, no. 4, p. 322.
4. Kuzmina, E.M, Kuzmina, I.N., Petrina, S.E., et al., Stomatologicheskaya zabolevaemost’ naseleniya Rossii. Sostoyanie tkanei parodonta i slizistoi obolochki rta (Dental Morbidity in Russia. The State of Periodontal Tissues and Oral Mucosa), Yanushevich, O.O., Ed., Moscow: MGMSU, 2009.
5. Shaju, J.P., Zade, R.M., and Das, M., Prevalence of Periodontitis in the Indian Population, J. Indian Soc. Periodontol., 2011, vol. 15, no. 1, p. 29.