Moffatt, C.W. Paget
University Tutorial Press, 1`929
Buku Teks
Kirk-Greene, C. W. E.
Foulsham, 1992
Buku Teks
Dampier, William Cecil
Cambridge University Press, 1989
Buku Teks
Tippett-Spirtou, Sandy, author
Routledge, 1999
Buku Teks
Coultas, Barbara, author
Teach Yourself Books, 1990
Buku Teks