RT Journal Article SR Electronic T1 A Global Approach to Portfolio Management JF The Journal of Portfolio Management FD Institutional Investor Journals SP 40 OP 48 DO 10.3905/jpm.1975.408512 VO 1 IS 2 A1 Roger H. Cass YR 1975 UL https://pm-research.com/content/1/2/40.abstract AB