@book {Kor-LZ-2009,
	title = {Lernbausteine Zahlenmauern},
	year = {2009},
	note = {230 Noppenbausteine mit Praxisbuch.},
	publisher = {Terzio Verlag},
	organization = {Terzio Verlag},
	keywords = {material},
	url = {http://www.book2look.com/vBook.aspx?id=6N4Ovvpbs9},
	author = {Ulrich Kortenkamp}
}
