Kidner, Richard
Blackstone, 1998
Buku Teks
Moskow, Michael H., author
Random House, 1970
Buku Teks
Schneider, Erich, author
George Allen and Unwin, 1963
Buku Teks
Twomey, David P.
South-Western Publishing Company, 1986
Buku Teks
Player, Macka
West Publishing, 1992
Buku Teks