@book{86134,
	author = {Tveito, Aslak, and Winther, Ragnar.},
	title = {Introduction to partial differential equations :},
	publisher = {Springer,},
	year = {c2009.},
	series = {Texts in applied mathematics,},
	address = {Berlin :},
	note = {Originally published: Berlin ; New York : Springer, c2005.}
}