@book{858, author = {Kreyszig, Herbert and Kreyszig, Erwin}, title = {Advanced engineering mathematics :}, publisher = {John Wiley & Sons,}, year = {2001.}, address = {New York :}, edition = {8th ed.}, url = {https://www.amazon.com/Advanced-Engineering-Mathematics-Erwin-Kreyszig/dp/0470458364} }