The Statistics of Communications Common Carriers (SOCC), which has been published annually since 1939, is one of the most widely used reference works in the field of telecommunications.  It is the only permanent record of common carrier activity published by the Government Printing Office and sent to repository libraries.  The most recent edition may be purchased by mail from the Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 15250-7954, or by calling GPO's Order and Inquiry Desk at (866) 512-1800.