Meskipun Gan Ying tak pernah sampai Roma, hanya berjalan paling jauh ke "laut barat" yang merujuk kepada Laut Hitam atau pesisir Parthia dari Teluk Persia, ia merupakan orang Tionghoa yang pergi ke wilayah paling barat pada zaman kuno, setidaknya dalam catatan-catatan sejarah, dan ia mengumpulkan informasi yang ia dapatkan.
"The Roman Empire in Chinese sources", Leslie and Gardiner, Rome, Bardi, 1996.
Hill, John E. 2004. The Peoples of the West from the Weilüe 魏略 by Yu Huan 魚豢: A Third Century Chinese Account Composed between 239 and 265 CE. Draft annotated English translation. [1]Diarsipkan 2017-12-23 di Wayback Machine.
Hill, John E. (2009) Through the Jade Gate to Rome: A Study of the Silk Routes during the Later Han Dynasty, 1st to 2nd Centuries CE. BookSurge, Charleston, South Carolina. ISBN 978-1-4392-2134-1.
Yu, Taishan. 2004. A History of the Relationships between the Western and Eastern Han, Wei, Jin, Northern and Southern Dynasties and the Western Regions. Sino-Platonic Papers No. 131 March, 2004. Dept. of East Asian Languages and Civilizations, University of Pennsylvania.