Tinbergen, J Statistical testing of business - cycle theories - New York Agathon press inc. 1968 - 244p.; 22cm. - Contents : I A Method and its application to investment activity, II Business cycles in the United States of America 1919 - 1932 . Subjects--Topical Terms: Business theoriesCorrelation analysisEconometricsEconomics - mathematical methodsInvestmentStatistical testing