The designation "Šumava" has been attested in the late 15th century in Antonio Bonfini's work "Rerum unganicarum decades". Folk etymology connects the name's origin with the Czech words "šum, šumění" (literally "hum, humming") denoting the noise of trees in the wind. The most accepted opinion among linguists derives Šumava from a theorized Proto-Slavic word '*šuma = "dense forest", cf. Serbian "šuma as it adjoins regions populated by Serbs of Lusatia and surrounds (North Eastern Bavaria and Saxony)." There are corresponding toponyms in modern day Serbia (Balkans) i.e. Šumadija (land of dense forests).