yán jiū / huá qiáo shǐ / shí / tā / zhuān mén / chá yuè le / sì yì / dì qū / yí mín / wǎng lái / de / dàng àn

研究华侨史时，他专门查阅了四邑地区移民往来的档案。

While studying the history of overseas Chinese, he specifically consulted records of migration to and from the Siyi region.