Trevelyan, George Macaulay, 1876-1962, author
Longmans, Green, 1945
Buku Teks
Bindoff, S.T., author
Penguin Books, 1951
Buku Teks
Lavell, C.F., author
Macmillan, 1919
Buku Teks
Wilson, Charles E., author
Harper and Row, 1983
Buku Teks
Chapman, Stephen J., author
McGraw-Hill, 1991
Buku Teks