1. Periodontology;Beube,1953
2. Diseases of the Soft Structures of the Teeth and Their Treatment;Prinz,1939
3. Traumatic Occlusion;McCall;J. Am. Dent. A.,1939
4. Orthodontic Theory and Practice;Hemley,1953
5. Orthodontics—Principles and Prevention;Salzmann,1957