@book{221014,
	author = {United Nations.},
	title = {Measuring the economically active in population censuses},
	publisher = {United Nations},
	year = {2010.},
	series = {Studies in methods. Series F},
	address = {New York},
	note = {"ST/ESA/STAT/SER.F/102."},
	url = {http://unstats.un.org/unsd/demographic/sources/census/Entire%20Handbook.pdf}
}