PT - JOURNAL ARTICLE AU - Keith P. Ambachtsheer TI - International investing AID - 10.3905/jpm.1981.408829 DP - 1981 Oct 31 TA - The Journal of Portfolio Management PG - 23--27 VI - 8 IP - 1 4099 - https://pm-research.com/content/8/1/23.short 4100 - https://pm-research.com/content/8/1/23.full