Whiteman, Thomas
Zondervan, 1996
Buku Teks
McCarthy, Richard C.
[American Library association;American Library association, American Library association], 2007
eBooks
Cotsakos, Christos M.
Harper Business, 2000
Buku Teks
Walliman, Nicholas
Sage Publications Ltd , 2001
Buku Teks
Davenport, Dawn
Broadway Books, 2006
Buku Teks