@book{248918,
	author = {Wigfield, Allan. and ebrary, Inc.},
	title = {Development of achievement motivation},
	publisher = {Academic Press,},
	year = {c2002.},
	series = {Educational psychology series},
	address = {San Diego :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10172774}
}