← Search Econometrica Vol. 38 No. 5 1970 Fundamental Methods of Mathematical Economics Ivan Bello; Alpha C. Chiang DOI10.2307/1912217 Volume38 Issue5 Pages787 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 ✓