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3. The World Health Organization (2009) WHO Handbook on Indoor radon. ISBN 978-92-4-154767-3. Available at: http://whqlibdoc.who.int/publications/2009/9789241547673_eng.pdf.
4. UNSCEAR United Nation Scientific Committee on the Effect of Atomic Radiation (2000). Annex B: exposures from natural radiation sources. United Nations, p 104
5. ICRP (International Commission on Radiological Protection) (2011) Lung cancer risk from radon and progeny and statement on radon. ICRP Publication-115 Pergamon Press