RT Journal Article SR Electronic T1 The Economics of the Market in Modern Prints JF The Journal of Portfolio Management FD Institutional Investor Journals SP 25 OP 32 DO 10.3905/jpm.1980.408779 VO 7 IS 1 A1 Robert E. Penn YR 1980 UL https://pm-research.com/content/7/1/25.abstract AB