Paine, Thomas, author
David Campbell Publishers, 1994
Buku Referensi
Vinogradoff, Paul, 1854-1925, author
Oxford University Press, 1956
Buku Teks
Wagner, Wolgang, author
Palgrave Macmillan, 2005
Buku Teks
Albrecht, Karl, 1941-
Josseey-Bass, 2007
Buku Teks
Conant, James B.
Yale University Press, 1964
Buku Teks