Berman, Barry, author
Prentice-Hall, 2001
Buku Teks
Din, Rasshied, author
Conran Octopus, 2000
Buku Referensi
Berman, Barry, author
Prentice Hall International, 1998
Buku Teks
Smith, Henry, author
Oxford University Press, 1951
Buku Teks
Rachman, David J., author
Prentice-Hall, 1969
Buku Teks