Doelle, Meinhard, author
Carswell, 2009
Buku Teks
Tabb, William Murray, author
Michie, 1992
Buku Teks
Gray, Oscar S.
The Bureau of National Affairs, 1973
Buku Teks
Stewart, Richard B.
The Bobbs-Merrill Company,Inc., 1978
Buku Teks
Craig, Robin Kundis
Thomson/West, 2008
Buku Teks