1. Differential diagnosis and treatment of root angulation problems;Bert;Dent Clin North Am,1981
2. Postmortems in post-treatment adjustment;Graber;Am J Orthod,1966
3. The philosophy of the tooth positioning appliance;Kesling;Am J Orthod,1945
4. The vacuum formed dental contour appliance;Nahoum;N Y State Dent J,1964
5. Invisible retainers;Ponitz;Am J Orthod,1971