Little,Brown and Company, [Date of publication not identified]
Buku Teks SO
Schroeder, Milton R.
Warren, Gorham & Lamont, 1995
Buku Teks
Hazen, Thomas Lee
West Publishing, 1996
Buku Teks
Mann, Richard A.
South Western Cengage Learning, 2011
Buku Teks
Brazier, Gil
Cavendish, 1996
Buku Teks SO