RT Journal Article SR Electronic T1 A new approach to ratings on utility bonds JF The Journal of Portfolio Management FD Institutional Investor Journals SP 73 OP 74 DO 10.3905/jpm.1980.408755 VO 6 IS 4 A1 Richard B. Edelman YR 1980 UL https://pm-research.com/content/6/4/73.abstract AB