Shiva Purana
शिवानुग्रहतस्तत्र गंगा नाम्ना तु गौतमी ॥ संस्थिता गौतमप्रीत्या पावनी शंकरप्रिया ॥ ३७॥
With the blessings of Śiva, and pleased with Gautama, the holy river Gaṅgā, the beloved of Śiva, stayed there in the name of Gautamī.
english translation
zivAnugrahatastatra gaMgA nAmnA tu gautamI ॥ saMsthitA gautamaprItyA pAvanI zaMkarapriyA ॥ 37॥
hk transliteration by Sanscript