Shiva Purana
यस्तु गंगा सरिच्छ्रेष्ठामवातारयतः प्रभु ॥ समुद्रमानयच्चेमां दुहितृत्वमकल्पयत्॥ ८॥
It was this Bhagīratha who brought Gaṅgā to the sea and made her his daughter.
english translation
yastu gaMgA saricchreSThAmavAtArayataH prabhu ॥ samudramAnayaccemAM duhitRtvamakalpayat॥ 8॥
hk transliteration by Sanscript