@book{39512,
	author = {Minnesota Symposium on Child Psychology and Hill, John P., and ebrary, Inc.},
	title = {Minnesota symposia on child psychology.},
	publisher = {University of Minnesota Press,},
	year = {1971.},
	series = {Minnesota symposia on child psychology (Series)},
	address = {Minneapolis :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10231113}
}