Columbia subject headings:
Harvard subject headings:
Helos Plain (Greece)--History.
Human settlements--Greece--Helos Plain--History.
Land settlement patterns--Greece--Lakōnia.
Land settlement--Greece--Helos Plain--History.
Land use, Rural--Greece--Lakōnia.
Princeton subject headings:
Helos Plain (Greece)--History.
Helos Plain (Greece)--Rural conditions.
Rural development--Greece--Helos Plain--History.