Urethral dilators.
Kravetz
Robert E
RE
Archives Committee, American College of Gastroenterology, USA.
D049671:History, 18th Century; D049672:History, 19th Century; D049690:History, Ancient; D006801:Humans; D013525:Surgical Instruments / Q000266:history*; D014525:Urethral Stricture / Q000175:diagnosis / Q000266:history* / Q000628:therapy