1. Halliday HL, McClure BG, Reid M. Handbook of neonatal intensive care (4th edn).London: WB Saunders Company Limited, 1998.
2. Commission of the European Communities (Lake Starnberg Group). Quality criteria for diagnostic radiographic images in paediatrics.Brussels: Commission of the European Communities, 1992.
3. International Commission on Radiological Protection. Recommendations of the International Commission on Radiological Protection. ICRP publication No. 60.Oxford: Pergamon Press, 1990.
4. Hart D, Jones DG, Wall BF. Coefficients for estimating effective doses from paediatric X-ray examinations, NRPB-R279.Chilton: HMSO, 1996.
5. Hospital Physicists Association (diagnostic radiology topic group). The physics of radiodiagnosis: scientific Report No. 6 (2nd edn).London: Hospital Physicists Association, 1977.