Oxford University Press, 2012
Buku Teks
Stone, Geoffrey R.
Little, Brown and Company, 1991
Buku Teks
Wade, E. C. S. (Emlyn Capel Stewart), author
Longmans Green, 1951
Buku Teks
Wade, E. C. S. (Emlyn Capel Stewart), author
[publisher not identified], [date of publication not identified]
Buku Teks
Nowak, John E., author
Thomson/West, 2010
Buku Teks