@book{53970,
	author = {Erickson, Martin J.,},
	title = {Introduction to combinatorics /},
	publisher = {Wiley,},
	year = {2013.},
	series = {Wiley Series in Discrete Mathematics and Optimization},
	address = {Hoboken, New Jersey :},
	edition = {Second edition.},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10895758}
}