1. Banks, P. A. andRead, M. J. F. (1987): ‘An investigation into the reliability of the Timing headgear,’Br. J. Orthodontics,14, 263–267
2. Broekman, R. W. (1969): ‘The co-operation of patients in orthodontic treatment,’Oral Res. Abstr.,4, p. 432
3. Clemmer, J. E. andHayes, E. W. (1979): ‘Patient co-operation in wearing orthodontic headgear,’Am. J. Orthodontics,75, 517–524
4. Cureton, S. L., Regennitter, F. andOrbell, M. G. (1991): ‘An accurate, inexpensive headgear timer,’J. Clin. Orthodontics,25(12), 749–754
5. Northcutt, M. E. (1974): ‘The timing headgear,’J. Clin. Orthodontics,8, 321–324