《旧唐书·本纪·卷十二》
九日，以伊西、北庭节度留后杨袭古为北庭大都护、伊西、北庭节度使、度支使、营田使、瀚海使。
丁酉，以伊西北庭节度留后杨袭古为北庭大都护、伊西北庭节度度支营田瀚海等使。
On the 9th, Yang Xigu, Prefect of Xigang and Beiting, was appointed Grand Protectorate of Beiting and Jiedushi of Xigang and Beiting. He was also given the additional posts of Administrator of the Office of Revenue and Expenditure, Administrator of the Military Farms, and Administrator of Hanghai.