Mitchell, Wesley C. What happens during business cycles : a progress report / Wesley C. Mitchell - New York : National Bureau of Economic Research (NBER) , 1951 - xxxi, 386p. : ill ; 24 cm. - Studies in business cycles . Includes bibliographical references and index. Subjects--Topical Terms: Economic fluctuationsBusiness cycles Dewey Class. No.: 338.54 / MIT-2