edited by George W. Turner
Melbourne, Oxford University Press, 1987
Buku Referensi
Oxford : Oxford University Press, 1995,
Buku Referensi
Oxford university press , 1992
Buku Teks
edited by Della Thompson
Oxford University Press, 1996
Buku Referensi
Hornby, Albert Sydney
Oxford University Press, 1984
Buku Referensi