Gaultney, Jane F., author
California, 2007
Buku Teks
Howitt, Dennis, author
Routledge, 2000
Buku Teks
Jackson, Sherri L., author
Cengage Learning, 2015
Buku Teks
Pittenger, David J., author
McGraw-Hill, 2003
Buku Teks
Craig, James R., author
Saunders, 1986
Buku Teks