Letter: Natural radioactivity in ilmenite aggregates.
D003252:Construction Materials; D011197:Potassium Radioisotopes / Q000032:analysis*; D013910:Thorium / Q000032:analysis*; D014501:Uranium / Q000032:analysis*
D011197:Potassium Radioisotopes; D014501:Uranium; D013910:Thorium