RT Journal Article SR Electronic T1 Rating classification and bond yield volatility JF The Journal of Portfolio Management FD Institutional Investor Journals SP 51 OP 57 DO 10.3905/jpm.9.3.51 VO 9 IS 3 A1 John M. Cheney YR 1983 UL https://pm-research.com/content/9/3/51.abstract AB