Little,Brown and Company, [date of publication not identified]
Buku Teks
Tabb, William Murray
The Michie Company, 1992
Buku Teks
Cooper, Phillip J.
Thomson Wadsworth, 2005
Buku Teks
Dolgin, Erica L.
West Publishing Company, 1997
Buku Teks
Rodgers, William H.
St. Paul Minn, 1977
Buku Teks