← Search Journal of Finance Vol. 20 No. 3 1965 Portfolio Selection and Investment Performance Irwin Friend; Douglas Vickers DOI10.2307/2977990 Volume20 Issue3 Pages391 Sources openalex crossref semanticscholar 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 ✓