《明史·列传·卷一百一十一》
卢沟发源于桑干河，滹沱发源于泰戏河，源远流长。
卢沟发源于桑乾，滹沱发源于泰戏，源远流长。
The Lugou River originated from the Sanggan River, and the Hutuo River originated from the Taxihe River. Both rivers had a very long headstream.