1. Periodontal disease, bacteria, and pulpal histopathology;Langeland;Oral Surg Oral Med Oral Pathol,1974
2. A textbook of oral pathology;Shafer,1983
3. The dental pulp;Seltzer,1985
4. Endodontic practice;Grossman,1988
5. Endodontic therapy;Weine,1989