《北史·列传·卷八十六》
延兴五年予成请求通婚聘。有司因予成屡次进犯边塞，请拒绝他的使者，出兵讨伐。
延兴五年，予成求通婚聘，有司以予成数犯边塞，请绝其使，发兵讨之。
In 473, Yucheng requested marriage. The authorities rejected his envoy and sent troops to punish him because Yucheng had repeatedly invaded the border.