《水经注·卷二十五》
桑泉水又往东南流与望尚水汇合，此水有两条源流，东流合为一条，俗称汉水。
又东南与崮水合，水有二源双会，东导一川，俗谓之汶水也。
Sangquan water flows southeast again and merges with Wangshang water. This water has two sources, which flow eastward and merge into one, commonly known as Han water.