Analysis of information sources in references of the Wikipedia article "Alans" in English language version.
Yan Shigu's 顏師古 commentary says: "Hu Guang 胡廣 adds: "Some 1,000 li to the north of Kangju was a state named Yancai, which also was named Hesu. Hence Hesu was identical with Yancai." This shows that the Yancai were also called the Hesu in the Han times.