Columbia subject headings:
Harvard subject headings:
Government communication systems--Purchasing--United States.
Government purchasing--United States.
Public contracts--United States.
Telecommunication systems--Purchasing--United States.
Telecommunication systems--United States--Purchasing.
Princeton subject headings:
Government communication systems--United States--Purchasing.
Government purchasing--United States.
Public contracts--United States.
Telecommunication systems--United States--Purchasing.