1. Sicher, Harry: Personal communication.
2. A Selection of Forces for Tooth Movement;Halderson;Am. J. Orthodontics,1953
3. Krogman, Wilton Marion: Personal communication.
4. The Importance of the Tongue in the Development of Normal Occlusion;Swinehart;Am. J. Orthodontics,1950
5. Notes, Denver Summer Meeting;Moore,1954