Johson, David B., author
Grove Brooks/Cole, 1999
Buku Teks
Plummer, David T., author
MacGraw-Hill, 1978
Buku Teks
Conover, W.J., author
John Wiley & Sons, 1980
Buku Teks
Vogel, Arthur I., author
The English Language Book Society, 1966
Buku Teks
Vogel, Arthur I., author
English Language Book Society, 1958
Buku Teks