AltmanD. G. (1980) Statistics and ethics in medical research. III. How large a sample?British Medical Journal, 281, 1336–1338.
2.
HeasmanP. A., MacGregorI. D. M., WilsonZ. and KellyP. J (1998) Toothbrushing forces in children with fixed orthodontic appliances, British Journal of Orthodontics, 25, 187–190.
3.
MachinD. and CampbellM. G. (1987) Statistical Tables for the Design of Clinical Trials, Blackwell, Oxford.
4.
NewcombeR. G. (2000a) Statistical methods in orthodontics. Part I. Confidence intervals: an introduction. Journal of Orthodontics, 27, 270–272.
5.
NewcombeR. G. (2000b) Statistical methods in orthodontics. Part II. Confidence intervals for proportions and their differences, Journal of Orthodontics, 27, 339–340.
SargisonA. E., McCabeJ. F. and MillettD. T. (1999) A laboratory investigation to compare enamel preparation by sandblasting or acid etching prior to bracket bonding. British Journal of Orthodontics, 26, 141–146.