1. Double canals in single roots;Green;Oral Surg.,1973
2. Endodontics;Ingle,1976
3. Pineda, F., and Kuttler, Y.: Mesiodistal and buccolingual roentgenographic investiga tion of 7, 275 root canals. Oral Surg., 33.101-110, 1972.
4. Principles of Pre-Clinical Endodon tics;Serene,1975
5. Endodontic Therapy;Weine,1976