David A. Hofmann, Michael Frese, editor
Routledge, 2011
Buku Teks
Greenberg, Jerald, author
Prentice-Hall, 2000
Buku Teks
Reitz, H. Joseph
richard D. Irwin, 1977
Buku Teks
Barron, Robert A., author
Allyn and Bacon, 1990
Buku Teks
Cohen, Allan R., author
McGraw-Hill, 2001
Buku Teks