title: Either-or? (Why not both?)
mesh_terms: D000337:Aerospace Medicine / Q000266:history; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D008887:Military Medicine / Q000266:history; D012106:Research / Q000266:history; D012129:Respiratory Function Tests / Q000266:history*; D014481:United States