1. Current procedural terminology for periodontics and insurance reporting manual,1991
2. Diagnosing periodontal diseases;Barrington;JADA,1990
3. Classification of periodontal diseases;Ranney;Periodontol 2000,1993
4. Diagnosis and classification of the periodontal diseases;Suzuki;Dent Clin North Am,1988
5. Tooth loss with and without periodontal therapy;Oliver;Periodont Abstr,1969