1. Descriptive Anatomy of the Human Teeth;Black,1902
2. A Consideration of the Deciduous Teeth and the Prevention of Dental Anomalies;Brandhorst;Washington Univ. Dent. J.,1937
3. The Growth of the Jaws, Normal and Abnormal;Brash,1924
4. Orthodontics: Principles and Practice;Graber,1961
5. Ibid., p. 252.