Batty, J
The English Languange Book Society, 1979
Buku Teks
Alford, Leon Pratt
Ronald Press, 1940
Buku Teks
Filipetti, George
Richard D. Irwin, 1959
Buku Teks
Owens, Richard N.
Richard D. Irwin, 1969
Buku Teks
Alford, Leon Pratt
Ronald Press, 1951
Buku Teks