References
- Barrer, H. G. (1975) Protecting the integrity of mandibular incisor position through keystoning procedure and spring retainer appliance, Journal of Clinical Orthodontics, 8, 486–494.
- Isaacson, K. E. and Williams, J. K. (1978) An introduction to Fixed Appliance, 2nd edn, John Wright, Bristol.
- Sandler, P. J. and Reed, R. T. (1988) Removable retainers: a modification of the Barrer appliance, British Journal of Orthodontics, 15, 127–129.