References
- O'Brien, K. D., Shaw W. C. and Roberts, C. T. (1993) The use of occlusal indices in assessing the provision of orthodontic treatment by the hospital orthodontic service of England and Wales, British Journal of Orthodontics, 20, 25–35.
- Office of Populations Censuses and Surveys (1983 Preliminary Report for Towns, Urban and Rural Populations, HMSO, London.
- Richmond, S., Shaw, W. C., Stephens, C. D., O'Brien, K. D., Buchanan, I. B., Jones, R., Roberts, C. and Andrews, M. (1992) The development of the PAR index (Peer Assessment Rating): reliability and validity. European Journal of Orthodontics, 14, 125–139.
- S.A.S. (1991) JMP, Statistical Visualization for the Apple Macintosh, S.A.S. Institute Incorporated, Cary, NC.