Journal Article Liefmann's Grundsätze der Volkswirtschaftslehre Get access G. A. Kleene G. A. Kleene Trinity College, Hartford, Conn. Search for other works by this author on: Oxford Academic Google Scholar The Quarterly Journal of Economics, Volume 35, Issue 3, May 1921, Pages 461–468, https://doi.org/10.2307/1884096 Published: 01 May 1921