RT Journal Article SR Electronic T1 Sour Dough is Hardly Pumpernickel JF The Journal of Portfolio Management FD Institutional Investor Journals SP 1 OP 1 DO 10.3905/jpm.1993.1 VO 19 IS 3 A2 Peter L. Bernstein YR 1993 UL https://pm-research.com/content/19/3/1.abstract AB