Stone, Geoffrey R.
Little, Brown and Company, 1991
Buku Teks
Wade, E.C.S. (Emlyn Capel Stewart)
Longmans Green, 1951
Buku Teks
Wade, E.C.S. (Emlyn Capel Stewart)
[publisher not identified], [date of publication not identified]
Buku Teks
Nowak, John E.
Thomson/West, 2010
Buku Teks
Fisher, Louis
McGraw-Hill, 1988
Buku Teks