《后汉书·列传·南蛮西南夷列传》
其中珠崖、儋耳两个郡在海岛上，东西长一千里，南北长五百里。
其珠崖、儋耳二郡在海洲上，东西千里，南北五百里。
Among them, the two counties of Zhuya and Dan'er are on the islands, 1,000 miles long from east to west, and 500 miles long from north to south.