1. Singh G. Retention and relapse in orthodontics. In: Textbook of Orthodontics, 3rd edition, ed. Singh G. The Health Sciences Publishers, Philadelphia, PA, Chapter 24, 2015, pp. 277.
2. Vaden JL, Klontz H, Dale J. Standard edgewise: tweed Merrifield philosophy, diagnosis, treatment planning and force systems. In: Current Principles and Techniques, 6th edition, ed. Graber LW, Vanarsdall RL, Vig KWL, Hwang GJ, Elsevier, St. Louis, Missouri, Chapter 19, pp. 485.
3. The decision to extract II. Analysis of clinicians’ stated reasons for extraction;Baumrind;Am J Orthod Dentofacial Orthop,1996
4. Glossary of orthodontic terms;Daskalogiannakis;Am J Orthod Dentofacial Orthop,2002