並前往https://www.cambridge.org/core/journals/journal-of-southeast-asian-history/article/prospects-for-east-sumatran-plantation-industries-a-symposium-ed-douglas-s-paauw-and-others-new-haven-conn-yale-university-southeast-asia-studies-1962-mongraph-series-no3-ppxiii-68-maps-us275/4A8C334924CFD335A0EF0089A63756F3