Columbia subject headings:
Bulgaria--Administrative and political divisions--Maps.
Bulgaria--Economic conditions--1944-1989--Maps.
Bulgaria--Maps.
Bulgaria--Population--Maps.
Land use--Bulgaria--Maps.
Maps.
Harvard subject headings:
Princeton subject headings:
Bulgaria--Administrative and political divisions--Maps.
Bulgaria--Economic conditions--1944-1989--Maps.
Bulgaria--Maps.
Bulgaria--Population--Maps.
Land use--Bulgaria--Maps.
Maps.