RT Journal Article SR Electronic T1 Portfolio selection via factor analysis JF The Journal of Portfolio Management FD Institutional Investor Journals SP 27 OP 30 DO 10.3905/jpm.1980.408750 VO 6 IS 3 A1 Peter C. Ho A1 Alfred S. Paulson YR 1980 UL https://pm-research.com/content/6/3/27.abstract AB