RT Journal Article SR Electronic T1 How to Maximize Stationarity of Beta JF The Journal of Portfolio Management FD Institutional Investor Journals SP 45 OP 49 DO 10.3905/jpm.1981.408787 VO 7 IS 2 A1 Thomas M. Tole YR 1981 UL https://pm-research.com/content/7/2/45.abstract AB