RT Journal Article SR Electronic T1 Calendar-Adjusted Volatilities JF The Journal of Derivatives FD Institutional Investor Journals SP 23 OP 32 DO 10.3905/jod.1993.407875 VO 1 IS 2 A1 Galen Burghardt A1 Gerald A.. Hanweck, Jr YR 1993 UL https://pm-research.com/content/1/2/23.abstract AB