@book{22,
	author = {Punch, Keith.},
	title = {Introduction to social research :},
	publisher = {SAGE,},
	year = {2005.},
	address = {London ;},
	edition = {2nd ed.},
	note = {Previous ed.: 1998.},
	url = {http://www.loc.gov/catdir/enhancements/fy0657/2004099537-d.html}
}