Liebert, Robert M., 1942-, author
Prentice-Hall, 1995
Buku Teks
Le Roy, Michael K., author
Wadsworth and Cengage Learning, 2013
Buku Teks
Craig, James R., author
Saunders, 1986
Buku Teks
Le Roy, Michael K., author
Wadsworth, 2009
Buku Teks
Johnson, Janet Buttolph, 1950-, author
CQ Press, 2012
Buku Teks