Walton, Douglas
Cambridge University Press, 2006
Buku Teks
Foresman, Galen A.
Wiley Blackwell, 2017
Buku Teks
Chatfield, Tom
Sage, 2018
Buku Teks
Rainbolt, George W.
Wadsworth and Cengage Learning, 2012
Buku Teks
Richards, Tom
Addison-Wesley Pub. Co., 1989
Buku Teks