Epstein, Adam
Pearson/Prentice Hall, 2006
Buku Teks
Manchester, Colin
Routledge.Cavendish, Taylor & Francis Group, 2008
Buku Teks
Mark S. Lee, authror
Thomson, 2006
Buku Teks
Greene, Graham
Zephyr Books, 1947
Buku Teks
Pollard, Dave
Haynes Publishing, 1993
Buku Referensi