RT Journal Article SR Electronic T1 The Penalties of Incurring Unsystematic Risk JF The Journal of Portfolio Management FD Institutional Investor Journals SP 31 OP 35 DO 10.3905/jpm.1978.408645 VO 4 IS 3 A1 Marvin McClay YR 1978 UL https://pm-research.com/content/4/3/31.abstract AB