《水经注·卷四》
河水往南流经雷首山西边，山在河边，北距蒲坂三十里，就是《尚书》所说的壶口雷首。
河水南径雷首山西，山临大河，北去蒲坂三十里，《尚书》所谓壶口雷首者也。
The Yellow River flows southward on the west side of Lei Shou Mountain. The mountain is beside the river, thirty li to the north of Puchang, the same place referred to in the Book of Documents as Hukou Lei Shou.