title: History of external counting procedures.
mesh_terms: D049673:History, 20th Century; D006801:Humans; D007457:Iodine Radioisotopes; D007677:Kidney Function Tests / Q000379:methods; D009369:Neoplasms / Q000175:diagnosis; D010761:Phosphorus Radioisotopes; D011874:Radiometry / Q000266:history / Q000295:instrumentation; D012588:Scintillation Counting / Q000266:history* / Q000295:instrumentation / Q000379:methods; D014481:United States
chemical_list: D007457:Iodine Radioisotopes; D010761:Phosphorus Radioisotopes