Thompson, J.M.
Basil Blackwell, 1955.
Buku Teks
Carlyle, Thomas
E.P. Dutton, 1955
Buku Teks
Pollard, Sidney
Harvard University Press, 1965
Buku Teks
Salvemini, Gaetano
W.W. Norton & Company, 1962
Buku Teks
Gershoy, Leo
Appleton Century Crofts, 1938
Buku Teks