@book{3447,
	author = {Oppenheim, Alan v.  and Hamid Nawab ,S},
	title = {Signals and Systems.},
	publisher = {Pearson;},
	year = {2015.},
	address = {Noida :},
	edition = {2nd ed.},
	url = {https://books.google.com.pk/books/about/Signals_Systems.html?id=LwQqAQAAMAAJ&source=kp_book_description&redir_esc=y}
}