Lerner, Joshua, author
John Wiley & Sons, 2012
Buku Teks
Elsevier, 2014
eBooks
Farid. Fara Mademah Ahmad, author
Edinburgh University Press, 2012
Buku Teks
edited by Chris Hale, Carolyn Boyle, Jo Moore
Globe Business, 2010
Buku Teks
Holt, David H., author
Prentice-Hall, 1992
Buku Teks