@techreport{repORt:2015-030,
	author = {F.J.L. Willamowski and A. Bley},
	title = {A Constant-Factor Local Search Approximation for Two-Stage Uncapacitated Facility Location},
	institution = {Operations Research, RWTH Aachen University},
	year = {2015},
	number = {2015--030},
	month = {Nov}
}