McCarthy, Michael
Cambridge University Press, 1999
Buku Teks
Barker, D. W.
Macmillan and Co., 1953
Buku Teks
Griffin, Suzanne
BBC English, 1989
Buku Teks
Kierzek, John M.
Macmillan, 1951
Buku Teks
French, F. G., author
Oxford University Press, 1947
Buku Teks