title: Letter: HBAg subtypes in the Rome area.
mesh_terms: D006506:Hepatitis A / Q000209:etiology / Q000473:pathology; D006511:Hepatitis B Antigens / Q000302:isolation & purification*; D006801:Humans; D008099:Liver / Q000473:pathology; D012384:Rome
chemical_list: D006511:Hepatitis B Antigens