RT Journal Article SR Electronic T1 The CAPM and the Investment Horizon JF The Journal of Portfolio Management FD Institutional Investor Journals SP 32 OP 40 DO 10.3905/jpm.1981.408794 VO 7 IS 2 A1 Haim Levy YR 1981 UL https://pm-research.com/content/7/2/32.abstract AB