@book{222922,
	author = {Birkelund, Gunn Elisabeth.},
	title = {Class and stratification analysis},
	publisher = {Emerald,},
	year = {2013.},
	series = {Comparative social research,},
	address = {Bingley, U.K. :},
	url = {http://www.emeraldinsight.com/0195-6310/30}
}