Martin, Ross M., author
Penguin Books, 1980
Buku Teks
Laski, Harold J., author
George Allen and Unwin, 1960
Buku Teks
McIlroy, John, author
Manchester University Press , 1995
Buku Teks
Rees, Albert, author
University of Chicago Press, 1962
Buku Teks
Kilian, Michael
st Matins, 1982
Buku Teks