edited by Leonard D. White
University of Chicago Press, 1945
Buku Teks
Chapman, Richard A.
Constable, 1970
Buku Teks SO
Chant, Bent
Avon Books, 1994
Buku Teks
England. Cabinet Office
Her Majesty's Stationery Office, 1988
Buku Referensi
Dupre, Flint O
Harper & Row, 1967
Buku Teks