Columbia subject headings:
Harvard subject headings:
Telecommunication policy--United States
Telecommunication policy.
Telecommunication systems.
Telecommunication--United States
Telecommunication.
Telephone companies--United States.
Telephone.
Princeton subject headings:
Telecommunication policy--United States.
Telecommunication policy.
Telecommunication systems.
Telecommunication--United States.
Telecommunication.
Telephone--United States.
Telephone.