title: [2 unknown letters of Jan Jonston to elector of Brandenburg Frederick William].
mesh_terms: D005197:Famous Persons; D005858:Germany; D049670:History, 17th Century; D006801:Humans; D011044:Poland; D012577:Schools, Medical / Q000266:history*; D014956:Writing
vernacular_title: Dwa nieznane listy Jana Jonstona do elektora brandenburskiego Fryderyka Wilhelma.