《水经注·卷十一》
易水又东流，与濡水汇合。濡水发源于故安县西北穷独山的南谷，东流与源泉水汇合，源泉水发源于北溪，往东南流注入濡水。
易水又东与濡水合，水出故安县西北穷独山南谷，东流与源泉水合，水发北溪，东南流注濡水。
Yishui flows eastward again and joins with Rusui. Rusui originates from the southern valley of Qiong Dushan in the northwest of Gu'an County, flows east and joins with Yuanquan River. Yuanquan River originates from Beixi River and flows into Rusui from the southeast.