Gooch, R.K. (Robert Kent), 1893-1982
D. Van Nostrad, 1937
Buku Teks
Trevelyan, George Macaulay, 1876-1962
Longmans, Green, 1945
Buku Teks
Lavell, C.F.
Macmillan, 1919
Buku Teks
Stroud, Angus
Routledge, 1999
Buku Teks
Green, John Richard, editor
New York The Co-operative Publication Society [t.th.]
Buku Teks