Cyclical Changes in Corporate Profits W. L. Crum The Review of Economics and Statistics 1939 21(2), 49
Review of the Year 1938 W. L. Crum; Dorothy Wescott The Review of Economics and Statistics 1939 21(1), 40
Periodicity as an Explanation of Variation in Hog Production P. D. Bradley; W. L. Crum Econometrica 1939 7(3), 221