Verlinden, Jay
Wadsworth/Thomson Learning, 2005
Buku Teks
Rainbolt, George
Wadsworth and Cengage Learning, 2012
Buku Teks
Reichenbach, Bruce R.
McGraw-Hill, 2001
Buku Teks
Jackson, Debra
Wadsworth and Cengage Learning, 2012
Buku Teks
Ennis, Robert Hugh
Prentice-Hall, 1996
Buku Teks