Mackinnon, Danny, author
Routledge, 2019
Buku Teks
Mackinnon, Danny, author
Pearson, Prentice Hall, 2007
Buku Teks
Knox, Paul, author
Edward Arnold , 1994
Buku Teks
Thatcher, W.S., author
English University Press, 1957
Buku Teks
Wheeler, James O., author
John Wiley & Sons, 1986
Buku Teks