title: Seasonal periodicity in gastroduodenal ulcers.
authors.forename: Z
authors.initials: Z
authors.lastname: Tulassay
authors.forename: J
authors.initials: J
authors.lastname: Papp
authors.forename: G
authors.initials: G
authors.lastname: Lengyel
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer; D010507:Periodicity; D012621:Seasons