1. William′s PL, Bannister LH, Berry MM, Collins P, Dyson M, Dussek JE, et al. Gray′s Anatomy. In: The Teeth, 38 th Ed; London: Churchill Livingstone; 2000. pp. 1699-1700.
2. Black GV. Description of human teeth. 4 th Ed; Philadelphia S.S.White Mfg.co. 1902.
3. Kiesu JA. Human adult odontometrics. In: The study of variation in adult tooth size. Cambridge: University Press; 1990.