Columbia subject headings:
Ameritech.
Consolidation and merger of corporations--United States.
SBC Communications.
Telephone companies--United States.
Telephone--United States.
Harvard subject headings:
Ameritech
Consolidation and merger of corporations--United States.
SBC Communications.
Telephone companies--United States.
Telephone--United States
Princeton subject headings:
Ameritech.
Consolidation and merger of corporations--United States.
SBC Communications.
Telephone--United States.