Bladon, Rachel
Passport Books, [date of publication not identified]
Buku Teks
Whitmarsh, W. F. H.
Longmans, Green and Co., 1960
Buku Teks
Rybak, Stephanie
Macmillan and Co., 1985
Buku Teks
Spencer, R. A.
Edward Arnold & Co, [date of publication not identified]
Buku Teks
Barratt, William B.
Aldine House, 1994
Buku Teks