RT Journal Article SR Electronic T1 Duration JF The Journal of Portfolio Management FD Institutional Investor Journals SP 38 OP 43 DO 10.3905/jpm.1986.409079 VO 13 IS 1 A1 J.B. Gould A1 Eric H. Sorensen YR 1986 UL https://pm-research.com/content/13/1/38.abstract AB