title: Letter: Measurement of serum triiodothyronine concentrations.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D002648:Child; D006801:Humans; D008875:Middle Aged; D011863:Radioimmunoassay / Q000379:methods; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D014284:Triiodothyronine