RT Journal Article SR Electronic T1 Common Factors Affecting Bond Returns JF The Journal of Fixed Income FD Institutional Investor Journals SP 54 OP 61 DO 10.3905/jfi.1991.692347 VO 1 IS 1 A1 Robert B Litterman A1 Josè Scheinkman YR 1991 UL https://pm-research.com/content/1/1/54.abstract AB