Whitmarsh, W.F.H., author
Longmans, Green, 1960
Buku Teks
Rybak, Stephanie, author
Macmillan, 1985
Buku Teks
Barratt, William B., author
Aldine House, 1994
Buku Teks
Spencer, R.A., author
Edward Arnold, [Date of publication not identified]
Buku Teks
Skaife, Linda, author
National Textbook Company, 1994
Buku Teks