title: Ophthalmology and philately: IV, Ophthalmologic Congresses.-The 15th International Congress, 1937.
mesh_terms: D003226:Congresses as Topic / Q000266:history*; D004534:Egypt; D049673:History, 20th Century; D006801:Humans; D009885:Ophthalmology / Q000266:history*; D010678:Philately