RT Journal Article SR Electronic T1 Model indexation JF The Journal of Portfolio Management FD Institutional Investor Journals SP 37 OP 40 DO 10.3905/jpm.1991.409347 VO 17 IS 4 A1 Allan Twark A1 James P. D'mello YR 1991 UL https://pm-research.com/content/17/4/37.abstract AB