Le Roy, Michael K., author
Wadsworth and Cengage Learning, 2013
Buku Teks
Le Roy, Michael K., author
Wadsworth, 2009
Buku Teks
Johnson, Janet Buttolph, 1950-, author
CQ Press, 2012
Buku Teks
Le Roy, Michael K., author
Thomson Wadsworth, 2007
Buku Teks
Wiersma, William, author
Pearson/Allyn and Bacon, 2005
Buku Teks