Marriot, Bety Bowers, author
McGraw-Hill, 1997
Buku Referensi
Wood, Christopher, author
Addison-Wesley, 1998
Buku Teks
Gunter, Barrie, author
New Lawrence Erlbaum Associates Inc, 2005
Buku Teks
Watkins, L. H.
Prentice-Hall, 1981
Buku Teks
Canter, Larry W., author
McGraw-Hill, 1996
Buku Teks