1. Microscopic investigation of root apexes;Kuttler;JADA,1955
2. The anatomy of the root canals of the teeth of the permanent dentition;Hess,1925
3. The internal anatomy of the teeth with special reference to the pulp with its branches;Barrett;Dent Cosmos,1925
4. Anatomy of the root canals of the incisors, cuspids and bicuspids of the permanent teeth;Mueller;JADA,1933
5. Mesiodistal and buccolingual roentgenographlc investigation of 7,275 root canals;Pineda;Oral Surg,1972