The British Council and the Publisher Association, 1992
Buku Referensi
Winter, C.F. (Carel Frederik), author
Geofferey Cumberlege, 1948
Buku Teks
Cullingworth, J.B., author
Allen & Unwin, 1979
Buku Teks
Egerton, Hugh Edward, author
Methuen, 1905
Buku Teks
Marcham, Frederick George
Harper & Brothers, 1960
Buku Teks