Farrar, Harry, author
The Donnington Press, 1970
Buku Teks
Hill, Christopher, author
LLP, 2003
Buku Teks
Cremona, Marise, author
Macmillan, 1989
Buku Teks
Smith, J. C. (John Cyril), author
Butterworth, 1992
Buku Teks
Curzon, L. B., author
Pitman, 1994
Buku Teks