RT Journal Article SR Electronic T1 A Misleading Feature of Beta for Risk Measurement JF The Journal of Portfolio Management FD Institutional Investor Journals SP 31 OP 34 DO 10.3905/jpm.1977.408617 VO 3 IS 4 A1 John D. Martin A1 Arthur Keown YR 1977 UL https://pm-research.com/content/3/4/31.abstract AB