Franks, Norman L.R.
William Kimber, 1980
Buku Teks
Walker, Diana Barnato
Patrick Stephens, 1994
Buku Teks
Goodrich, Chauncey A., author
Bobbs-Merrill, 1963
Buku Teks
Her Majesty's Stationery Office, 1955
Buku Teks
Bromhead, Peter
Longman, 1992
Buku Teks