Biddulph, Dick. editor
Radio Society of Great Britain, 1994
Buku Referensi
edited by D.M. Balston and R.C.V. Macario
Artech House, c1993
Buku Teks
Wilby, Pete, author
Routledge, 1994
Buku Referensi
Orr, William I., author
Howard W. Sams , 1987
Buku Referensi
Skolnik, Merrill I., author
McGraw-Hill, 1980
Buku Teks