Hal Hill, author
ISEAS, 2001
eBooks
Cristalis, Irena, author
Palgrave Macmillan , 2009
Buku Teks
Bouvier, Leon F., author
Seven Lucks Press, 1999
Buku Teks
Flint, Colin, author
Pearson/Prentice Hall, 2007
Buku Teks
Flint, Colin, author
Taylor and Francis Group, 2018
Buku Teks