《史记·三十世家·田敬仲完世家》
宣王元年，秦国任用商鞅，周天子把霸主的称号授予秦孝公。
宣王元年，秦用商鞅。周致伯于秦孝公。
In the first year of King Xuan's reign, the State of Qin hired Shang Yang, and the emperor of the Zhou Dynasty gave the title of hegemon to King Xiao of Qin.