Specific radioactivities and related problems.
D008962:Models, Theoretical; D011197:Potassium Radioisotopes; D011829:Radiation Dosage; D011835:Radiation Protection / Q000592:standards*; D013910:Thorium; D014501:Uranium
D011197:Potassium Radioisotopes; D014501:Uranium; D013910:Thorium