Stroud, Angus
Routledge, 1999
Buku Teks
Trevelyan, George Macaulay, 1876-1962
Longmans, Green, 1948
Buku Teks
Stuart, Dorothy Margaret.
Macmillan, 1952
Buku Teks
Green, John Richard, editor
New York The Co-operative Publication Society [t.th.]
Buku Teks
Rose, Richard, 1933-
Scott, Foreman, 1989
Buku Teks