Harrington, Jon, author
Prentice-Hall, 1991
Buku Teks
Slater, Ken, author
Stockton Press, 1991
Buku Teks
Caeilli, William, author
Macmillan, 1991
Buku Teks
Cohen, Frederick B., author
John Wiley & Sons, 1995
Buku Teks
Calder, Alan, author
kogan page limited, 2005
Buku Teks