RT Journal Article SR Electronic T1 Prediction of common stock betas JF The Journal of Portfolio Management FD Institutional Investor Journals SP 5 OP 14 DO 10.3905/jpm.1985.408997 VO 11 IS 2 A1 Barr Rosenberg YR 1985 UL https://pm-research.com/content/11/2/5.abstract AB