Danielson, G. L. (George Lord)
The English Language Book, 1969
Buku Teks
Danielson, G. L. (George Lord)
Butterworth, 1981
Buku Teks
Freeman, Roger L., author
John Wiley & Sons, 1991
Buku Referensi
Roddy, Dennis, author
Erlangga, 1986
Buku Teks
Shrader, Robert L.
Erlangga, 1991
Buku Teks