"The Price of Wheat since 1867", Journal of Political Economy (JPE), Vol. 1, No. 1. (Dec., 1892), pp. 68-103; appendix pp. 156-161. [Text in html, using graphics!]
"The use of loan credit in modern business". Chicago, Ill.: University of Chicago Press, 1903, 22 p. from: Decennial publications of the University of Chicago. First series (Chicago, Ill.), vol. 4, p.31-50. (Republished without substantial change in The Theory of Business Enterprise).