London Merlin Press 1994,
Buku Teks
Plamenatz, John
National News-Letter, 1949
Buku Teks
Sweezy, Paul M. (Paul Marlor), 1910-2004
McGraw-Hill, 1949
Buku Teks
Carr, Edward Hallet
Macmillan, 1950
Buku Teks
Wilson, Edmund, 1895-1972
Doubleday, 1972
Buku Teks