Newman, Barbara M.
Thomson and Wadsworth, 2006
Buku Teks
Newman, Barbara M.
Cole Publishing, 1991
Buku Teks
Newman, Barbara M.
Wadsworth and Cengage Learning, 2012
Buku Teks
Bartol, Curt R.
Pearson Education, Inc., 2008
Buku Teks
Beland, Irene L.
Macmillan, 1981
Buku Teks