PT - JOURNAL ARTICLE AU - Keith P. Ambachtsheer TI - Can Selectivity Pay in an Efficient Market? AID - 10.3905/jpm.1976.408573 DP - 1976 Jul 31 TA - The Journal of Portfolio Management PG - 19--22 VI - 2 IP - 4 4099 - https://pm-research.com/content/2/4/19.short 4100 - https://pm-research.com/content/2/4/19.full