Batty, J
The English Languange Book Society, 1979
Buku Teks
Vance, Stanley C., author
McGraw-Hill , 1959
Buku Teks
Sayles, Leonard R., author
McGraw-Hill , 1964
Buku Teks
Barish, Norman N., author
Funk & Wagnalls Company, 1951
Buku Teks
Dale, Ernest, author
McGraw-Hill, 1973
Buku Teks