1. Radium in groundwater;Dickson,1990
2. Limits for Intakes of Radionuclides by Workers;ICRP,1979
3. 1990 Recommendations of the International Commission on Radiological Protection;ICRP,1991
4. The natural distribution of radium;Iyengar,1990
5. Internal radiation doses from radioactivity of drinking water in Finland;Kahlos;Health Phys.,1980