Bell Telephone Laboratories. (1971). Transmission systems for communications (Rev. 4th ed.). Bell Telephone Lab..
Chicago-referens (17:e uppl.)Bell Telephone Laboratories. Transmission Systems for Communications. Rev. 4th ed. New York: Bell Telephone Lab., 1971.
MLA-referens (8:e uppl.)Bell Telephone Laboratories. Transmission Systems for Communications. Rev. 4th ed. Bell Telephone Lab., 1971.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.