@book{31570,
	author = {Zhang, Yao},
	title = {Combinatorial problems in Mathematical competitions /},
	publisher = {Wspc/ecnu,},
	year = {2011},
	series = {Mathematical Olympiad series ; 4},
	address = {China:},
	note = {"Purchased under NBHM grant for the year 2011-2012"}
}