Não informado. (2003). Electrical Communication. International Telephone and Telegraph Corporation.
Chicago-referens (17:e uppl.)Não informado. Electrical Communication. New York: International Telephone and Telegraph Corporation, 2003.
MLA-referens (8:e uppl.)Não informado. Electrical Communication. International Telephone and Telegraph Corporation, 2003.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.
