@book{529093,
	author = {Zill, Dennis G., and Cullen, Michael R.},
	title = {Differential equations with boundary-value problems /},
	publisher = {National Book Foundation,},
	year = {c1993.},
	address = {Islamabad :},
	edition = {3rd ed. /},
	note = {Includes index.},
	url = {http://www.loc.gov/catdir/enhancements/fy1515/92017344-b.html}
}