1. IRCP 60: International Commission on Radiological Protection. Recommendations of the International Commission on Radiological Protection,1991
2. Exposure to unusually high indoor radon levels;Ennemoser;Lancet,1993
3. Residential radon exposure and lung cancer in Sweden;Pershagen;N Engl J Med,1994
4. Committee on the Biological Effects of Ionizing Radiation. Health effects of exposure to low levels of ionizing radiation;Beir,1990