1. Sherard, J.H., Jr. The Johnston-Callahan method of pulp canal cleansing and filling and the electrosterilization (ionization) technique. Atlanta, Emory University School of Dentistry, undated.
2. Sulfuric acid for opening root canals;Callahan;Dent Cosmos,1894
3. Accepted dental therapeutics 1969/70;Council on Dental Therapeutics,1968
4. Endodontic practice;Grossman,1965
5. Endodontics;Healey,1960