McCormick, Kathleen A.
Manchester University Press, 1994
Buku Teks
Mills, Paul
Routledge, 2006
Buku Teks
Brookes, Arthur
Cambridge University Press, 1990
Buku Teks
Cambridge University Press, 2010
eBooks
Palmer, Barbara C.
Allyn and Bacon, 1994
Buku Teks