title: Absolute determination of trace quantities of the 228Th series.
mesh_terms: D003879:Dermatologic Agents / Q000032:analysis; D010150:Paint / Q000032:analysis; D011883:Radium / Q000008:administration & dosage / Q000032:analysis; D012588:Scintillation Counting; D013910:Thorium / Q000032:analysis*; D013995:Time
chemical_list: D003879:Dermatologic Agents; D013910:Thorium; D011883:Radium