Não informado. (1974). Communication and broadcasting. Marconi Communication Systems.
Chicago-viite (17. p.)Não informado. Communication and Broadcasting. Chelmsford, Inglaterra: Marconi Communication Systems, 1974.
MLA-viite (8. p.)Não informado. Communication and Broadcasting. Marconi Communication Systems, 1974.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.