Rae, Leslie
McGraw-Hill, 1994
Buku Referensi
Mackenizie, John
Illinois: Dow Jones-Irwin, 1989
Buku Teks
Moss, Stephen R., author
Prentice-Hall, 2001
Buku Teks
Cope, Mick, author
Financial Times Prentice Hall, 2003
Buku Teks
Diggs, Steve
Golden Books Centre, 1990
Buku Teks