Hughes, Edward, author
Pearson Education, 2002
Buku Teks
edited by, Ian Inkster
Bloomsbury Publishing, 2012
Buku Teks
Howson, D. P. (David Philip), author
Pergamon Press, 1975
Buku Teks
Bartkiw, Walter L.
McGraw-Hill Ryerson, 1986
Buku Teks
Boylestad, Robert L., author
Prentice-Hall, 1983
Buku Teks