《旧唐书·本纪·卷十九》
李国昌仗恃功劳，颇为骄横。随便杀害官吏，朝廷无法驾驭，才调他去镇守云中。
国昌恃功颇横，专杀长吏，朝廷不能平，乃移镇云中。
Li Guochang, relying on his merits, was rather arrogant. He killed officials at will, and the court was unable to control him, so he was transferred to garrison Yunzhong.