@book{2447,
	author = {Liu, C L and Mohapatra, D P},
	title = {Elements of Discrete Mathematics :},
	publisher = {McGraw Hill,},
	year = {©2013.},
	address = {New Delhi :},
	edition = {4th ed.},
	url = {https://www.expresslibrary.mheducation.com/product/element-discrete-mathematics-sie50044959}
}