M. Stodółkiewicz, J. Krawczyk, J. Szkutnik, and M. Berger, “The assessment of periodontal status and treatment needs of the adult population aged 34-44 residing in Lublin province and visiting the dentist regularly”, Pol J Public Health, vol. 124, no. 2, pp. 86–88, Jul. 2014, doi: 10.2478/pjph-2014-0019.