Forrest-Thomson, Veronica, author
Manchester University Press, 1978
Buku Teks
Brecht, Arnold, author
Princenton University Press, 1968
Buku Teks
Hall, Peter, author
Blackwell, 2002
Buku Teks
Schapiro, J. Salwyn
McGraw-Hill Book Company, Inc., 1950
Buku Teks
Academic Press , 1988
Buku Teks