《明史·志·卷六十四》
当时，巡抚张国彦、副使顾养谦刚刚开通水利工程于蓟、永有功效，于是，给事中王敬民推荐徐贞明，特地召回，赐敕命勘测水利工程。
时巡抚张国彦、副使顾养谦方开水利於蓟、永有效，於是给事中王敬民荐贞明，特召还，赐敕勘水利。
At that time, the Governor Patroller Zhang Guoyan and Assistant Commissioner Gu Yangqian had just opened up a water conservancy project that had been effective in Ji and Yong, so the Surveillance Official Wang Jingmin recommended Xu Zhenming, who was then specially recalled and authorized by imperial edict to survey the water conservancy project.