York Penguin Book , 1965
Buku Teks
Ribner, Irving
Methuen , 1962
Buku Teks
edited by Russell A. Fraser and Norman Rabkin
Macmillan, 1976
Buku Teks
Salgado, Gamini
Macmillan Education, 1984
Buku Teks
Bradbrook, M.C. (Muriel Clara), 1909-1993, author
Cambridge University Press, 1980
Buku Teks