00561nam a2200145Ia 4500008004100000040001700041082002600058100002300084110005200107245007800159260005700237300001500294440003700309650006900346190328s9999||||xx |||||||||||||| ||und||  aNITILcNITIL  221sta338.5406bN277W  aMitchell, Wesley C  aNational Bureau of Economic Research (New York) 0aWhat happens during business cyclesba progress reportcWesley C Mitchell  aNew YorkbNational Bureau of Economic Researchc1951  axxxi, 386p  aStudies in business policy; no.5  aBusiness cycles; Economic fluctuation; Index numbers (Economics)