← Search Econometrica Vol. 31 No. 4 1963 Heterogeneous Capital and Smooth Production Functions: An Experimental Study Robert M. Solow DOI10.2307/1909163 Volume31 Issue4 Pages623 Sources semanticscholar openalex crossref Cite APA 7 MLA 9 Chicago (author–date) Harvard Elsevier Harvard (JFE, JBF…) The Accounting Review Academy of Management American Marketing Association INFORMS (Management Science) Copy citation Copied ✓