@book{178871,
	author = {Economic Commission for Europe.   },
	title = {Concentration indices in the  European coal industry :},
	publisher = {United Nations,},
	year = {1965.},
	series = {series F. no. 21 },
	address = {New york :},
	note = {"National accounts statistics, series X, no. 18, speical issue."}
}