@book{1320,
	author = {Kreyszig, Erwin},
	title = {Advanced engineering mathematics },
	publisher = {Wiley,},
	year = {1999.},
	address = {New York :},
	edition = {8th ed.},
	url = {https://www.amazon.com/Advanced-Engineering-Mathematics-Erwin-Kreyszig/dp/0470458364}
}