《汉书·传·公孙刘田王杨蔡陈郑传》
胜之完成使命回京，向皇上推荐王欣，武帝征召他任右辅都尉，代理右扶风。
胜之使还，荐欣，征为右辅都尉，守右扶风。
Bao Shengzhi completed his mission and returned to the capital, where he recommended Wang Xin to the emperor; Emperor Wu summoned him and appointed him as right supporting military commander, acting as the governor of Youfufeng county.