《汉书·传·匡张孔马传》
绥和年间，皇上即位二十五年，没有继承皂位的儿子，最亲的亲属有同母的弟弟中山孝王以及同母弟弟的儿子定陶王。
绥和中，上即位二十五年，无继嗣，至亲有同产弟中山孝王及同产弟子定陶王在。
During the Sui and He period, the emperor had been on the throne for 25 years, but had no heir, with his closest relatives being his maternal uncle Zhongshan Xiaowang, and his maternal uncle’s son, Dingtaowang.