EXHIBIT 21
PRINCIPAL SUBSIDIARIES OF SBC COMMUNICATIONS INC.
AS OF DECEMBER 31, 1997
State of Conducts
Name Incorporation Business Under
Southwestern Bell Missouri Same
Telephone Company
Southwestern Bell Dually incorporated in Same
Mobile Systems, Inc. Delaware and Virginia
SBC International, Inc. Delaware Same
Southwestern Bell Missouri Same
Yellow Pages, Inc.
SBC Media Ventures, Inc. Delaware Same
Pacific Telesis Group Nevada Same
PRINCIPAL SUBSIDIARIES OF SBC COMMUNICATIONS INC.
AS OF DECEMBER 31, 1997
State of Conducts
Name Incorporation Business Under
Southwestern Bell Missouri Same
Telephone Company
Southwestern Bell Dually incorporated in Same
Mobile Systems, Inc. Delaware and Virginia
SBC International, Inc. Delaware Same
Southwestern Bell Missouri Same
Yellow Pages, Inc.
SBC Media Ventures, Inc. Delaware Same
Pacific Telesis Group Nevada Same