Columbia subject headings:
Bulgarian language--Etymology--Names.
Montana (Bulgaria : Oblast)--History, Local.
Names, Geographical--Bulgaria--Montana (Oblast)
Harvard subject headings:
Bulgarian language--Etymology--Names.
Montana (Bulgaria : Oblast)--History, Local.
Names, Geographical--Bulgaria--Berkovit︠s︡a Region.
Names, Geographical--Bulgaria--Lom Region.
Names, Geographical--Bulgaria--Mikhaĭlovgradski okrug.
Princeton subject headings: