1. American College of Radiology, ACR Standards. ACR Standard for the performance of paediatric and adult chest radiography 2001; 1–5.
2. American College of Radiology. ACR Standards. ACR Standard for performing and interpreting diagnostic ultrasound examinations 2000; 1–2.
3. American College of Radiology. ACR Standards. ACR Standard for the performance of an ultrasound examination of the abdomen or retroperitoneum 2001; 1–5.
4. United Nations Scientific Committee on the Effects of Atomic Radiation UNSCEAR,. Report to the General Assembly, with Scientific Annexes. Sources and Effects of Ionizing Radiation, Volume I: Sources. New York: United Nations: Annex D Medical radiation exposures, 2000, 293–495.
5. Beentjes LB, Timmermans WM. Age and sex specific radiographic examination frequency in The Netherlands. Br J Radiol 1990; 63691–63697.