Shiva Purana
इंद्रद्युम्नः कसेरुश्च ताम्रवर्णो गभस्तिमान् ॥ नागद्वीपस्तथा सौम्यो गन्धर्वस्त्वथ वारुणः ॥ ४ ॥
Indradyumna and Kaseru were copper-coloured and radiant. The island of Nagadvipa is also known as Soumya Gandharva and Varuna.
english translation
iMdradyumnaH kaseruzca tAmravarNo gabhastimAn ॥ nAgadvIpastathA saumyo gandharvastvatha vAruNaH ॥ 4 ॥
hk transliteration by Sanscript