后汉书
Yule noted that although the description of the Roman Constitution and products was garbled, the "Book of the Later Han" offered an accurate depiction of the coral fisheries in the Mediterranean. Coral was a highly valued luxury item in Han China, imported among other items from India (mostly overland and perhaps also by sea), the latter region being where the Romans sold coral and obtained pearls. The original list of Roman products given in the "Book of the Later Han", such as sea silk, glass, amber, cinnabar, and asbestos cloth, is expanded in the "Weilüe". The "Weilüe" also claimed that in 134 AD the ruler of the Shule Kingdom (Kashgar), who had been a hostage at the court of the Kushan Empire, offered blue (or green) gems originating from "Haixi" as gifts to the Eastern Han court. Fan Ye, the editor of the "Book of the Later Han", wrote that former generations of Chinese had never reached these far western regions, but that the report of Gan Ying revealed to the Chinese their lands, customs and products. The "Book of the Later Han" also asserts that the Parthians (Chinese: 安息; "Anxi") wished "to control the trade in multi-coloured Chinese silks" and therefore intentionally blocked the Romans from reaching China.