Partington, J. R.
The English Language Book Society, 1965
Buku Teks
Barnett, E. de Barry, author
Longmans Green, 1957
Buku Teks
Wood, G.W.
Butterworth, 1960
Buku Teks
Bowser, James R., author
Brooks/Cole, 1993
Buku Teks
Shriver, D.F., author
ELBS, 1994
Buku Teks