RT Journal Article SR Electronic T1 How to tell if options are cheap JF The Journal of Portfolio Management FD Institutional Investor Journals SP 72 OP 78 DO 10.3905/jpm.1990.409259 VO 16 IS 2 A1 Galen Burghardt A1 Morton Lane YR 1990 UL https://pm-research.com/content/16/2/72.abstract AB