PT - JOURNAL ARTICLE AU - Tony Estep TI - Manager style and the sources of equity returns AID - 10.3905/jpm.1987.409092 DP - 1987 Jan 31 TA - The Journal of Portfolio Management PG - 4--10 VI - 13 IP - 2 4099 - https://pm-research.com/content/13/2/4.short 4100 - https://pm-research.com/content/13/2/4.full