Columbia subject headings:
Harvard subject headings:
Europe--Commerce--United States.
Telecommunication policy--Europe
Telecommunication policy--United States
Telecommunication systems--Europe.
Telecommunication systems--United States.
United States--Commerce--Europe.
Princeton subject headings:
Europe--Commerce--United States.
Telecommunication policy--Europe.
Telecommunication policy--United States.
Telecommunication systems--Europe.
Telecommunication systems--United States.
United States--Commerce--Europe.