Jex, Steve M., author
John Wiley & Sons, 2002
Buku Teks
Aamodt, Michael G., author
Wadsworth and Cengage Learning, 2013
Buku Teks
Aamodt, Michael G., author
Thomson/Wadsworth, 2004
Buku Teks
edited by P.J.D. Drenth ... [and others]
John Wiley & Sons, 1984
Buku Referensi
Edgell, Stephen, author
Sage , 2012
Buku Teks