Watson, Adam, author
Routledge, 1992
Buku Teks
Narvaez, Darcia, author
Oxford University Press, 2016
eBooks
Levine, Daniel U.
Allyn and Bacon, 1992
Buku Teks
Cook, David I., author
International Textbook Company, 1961
Buku Teks
Beck, Anatole
Worth, 1970
Buku Teks