Patwain, David, author
Routledge, 2002
Buku Teks
Mann, Leon
Sydney John Wiley & Sons 1969,
Buku Teks
Comer, Ronald J
New York W.H. Freeman and Co. 1998,
Buku Teks
Dewey, John, author
Buku Teks
Davison, Gerald C.
New York John Wiley & Sons 2000,
Buku Teks