Commager, Henry Steele, author
Dodd, Mead, 1965
Buku Teks
Bagehot, Walter
Oxford University Press, 1977
Buku Teks
Haley, Elie, author
Pelican Book, 1937
Buku Referensi
O`Connor, J.F., 1931-, author
Hants Gower, 1990
Buku Teks
Clarendon Press, 1991
Buku Teks