《后汉书·本纪·孝和孝殇帝纪》
九月二十日，帝视察南方，清河王刘庆、济北王刘寿、河间王刘开随从。
九月壬午，南巡狩，清河王庆、济北王寿、河间王开并从。
On September 20th, the emperor inspected the south, accompanied by King Liu Qing of Qinghe, King Liu Shou of Jibei, and King Liu Kai of Hejian.