Columbia subject headings:
Harvard subject headings:
Babylonia--History.
Euphrates River--Historical geography.
Iraq--Civilization.
Tigris River--Historical geography.
Tigris River--Social life and customs.
Tigris-Euphrates Delta (Iraq and Iran)
Princeton subject headings:
Babylonia--History.
Euphrates River--Historical geography.
Iraq--Civilization.
Tigris River--Historical geography.
Tigris River--Social life and customs.
Tigris-Euphrates Delta (Iraq and Iran)