Marjorie Howes, John Kelly, editor
Cambridge University Press, 2008
Buku Teks
Fraser, George Sutherland, 1915-
Published for the British Council and the National Book League by Longmans, 1965
Buku Teks
MacNeice, Louis
Oxford University Press, 1941
Buku Teks
Shannon, William V.
Macmillan, 1963
Buku Teks
Shannon, Robert E.
John Wiley & Sons, 1980
Buku Teks