title: Smallpox and variolisation in the populations on Bulgarian soil.
mesh_terms: D001208:Asia; D002031:Bulgaria; D005060:Europe; D049690:History, Ancient; D049691:History, Medieval; D049711:History, Modern 1601-; D006801:Humans; D007114:Immunization / Q000266:history*; D008519:Medicine, Traditional; D012899:Smallpox / Q000266:history*