@book{246949,
	author = {Abell, Martha L., and Braselton, James P.,},
	title = {Introductory differential equations / },
	publisher = {Academic Press,},
	year = {2014.},
	address = {Amsterdam :},
	edition = {4th ed.},
	url = {http://www.sciencedirect.com/science/book/9780124172197}
}