Shiva Purana
तत्र भुक्त्वा महाभोगान्कल्पकोटिशतन्नरः ॥ कालांतरेच्युतस्तस्मादौमं कौमारमेव च ॥ १९ ॥
After enjoying great pleasures there for hundreds of crores of kalpas In time Acyuta gave birth to Dauma and Kaumara.
english translation
tatra bhuktvA mahAbhogAnkalpakoTizatannaraH ॥ kAlAMtarecyutastasmAdaumaM kaumArameva ca ॥ 19 ॥
hk transliteration by Sanscript