Macnamara, Jim
Prentice Hall Australia, 1996
Buku Referensi
Hill, Dennis Cole
Golden Books Centre, 1992
Buku Teks SO
Jefkins, Frank William
Erlangga, 1996
Buku Teks
Jefkins, Frank William
Erlangga, 1996
Buku Teks
Jefkins, Frank William
Erlangga, 1996
Buku Teks