Carolyn Jackson, Claire Thurgate
McGraw-Hill, 2011
Buku Teks
Kirkwood, Colin
Sense, 2012
eBooks
editor, Siti Akmar Abu Samah
Univision Press, 2010
Buku Teks
Apps, Jerold W., author
Jossey-Bass , 1988
Buku Teks
Lengrand, Paul
Gunung Agung, 1970
Buku Teks