1. United Nations Scientific Committee on the Effects of Atomic Radiation. Sources and effects of ionizing radiation Vol. I Sources. UNSCEAR report 2008 report. UNSCEAR (2010).
2. United Nations Scientific Committee on the Effects of Atomic Radiation. Sources and effects of ionizing radiation Vol. I Sources. UNSCEAR report 2000 report. UNSCEAR (2000).
3. National Council on Radiation Protection and Measurements. Ionizing radiation exposure of the population of the United States. NCRP report No. 160. NCRP (2009).
4. Korea Food and Drug Administration. Study on the appropriate management of the diagnostic radiological devices. KFDA Research Report 2013. KFDA (2013). Available on http://report.ndsl.kr/repDetail.do?cn=TRKO201400011778 (Last accessed on 8 May 2015).
5. Organization for Economic Co-operation and Development. Complete databases available via OECD's iLibrary. OECD (2014). Available on http://stats.oecd.org (Last accessed on 8 May 2015).