Ur, Penny
Cambridge University Press, 1991
Buku Teks
Rivers, Wilga M.
Cambridge University Press, 1994
Buku Teks
Chastain, Kenneth
Rand McNally , 1971
Buku Teks
Ur, Penny
Cambridge University Press, 2006
Buku Teks
edited by Albert H. Marckwardt
National Council of Teachers of English, 1968
Buku Teks