Dreyer, C. J.Lewin, A.2016-04-212016-04-211967Dreyer, C. J., Lewin, A. 1967. Chronic periodontitis. Journal of the dental association of South Africa; 22(5):133-170http://hdl.handle.net/10539/20244PKenChronic PeriodontitisPeriodontiumChronic periodontitisArticle