PT - JOURNAL ARTICLE AU - Wilson Sy TI - Market timing AID - 10.3905/jpm.1990.409281 DP - 1990 Jul 31 TA - The Journal of Portfolio Management PG - 11--16 VI - 16 IP - 4 4099 - https://pm-research.com/content/16/4/11.short 4100 - https://pm-research.com/content/16/4/11.full