《周书·列传·卷十九》
魏恭帝初年，皇上赏赐杨忠姓普六如氏，让他兼摄同州的官职。
魏恭帝初，赐姓普六如氏，行同州事。
In the early years of Emperor Wei Gong, the emperor rewarded Yang Zhong with the surname Pulu Ruxu and let him concurrently hold the official position of Tongzhou.