Columbia subject headings:
Aqueducts--Bibliography.
Istanbul (Turkey). Aqueduct of Valens.
Water-supply--Turkey--Istanbul.
Harvard subject headings:
Aqueduct of Valens (Istanbul, Turkey)
Aqueducts--Turkey--Bibliography.
Istanbul (Turkey)
Istanbul (Turkey)--Buildings, structures, etc.
Water-supply--Turkey--Istanbul.
Princeton subject headings:
Aqueducts--Bibliography.
Istanbul (Turkey)--Aqueduct of Valens.
Water-supply--Turkey--Istanbul.