RT Journal Article SR Electronic T1 What can the future tell us about the past? JF The Journal of Portfolio Management FD Institutional Investor Journals SP 63 OP 66 DO 10.3905/jpm.1979.408721 VO 6 IS 1 A1 James R. Vertin YR 1979 UL https://pm-research.com/content/6/1/63.abstract AB