Shiva Purana
वर्षाणामष्टसाहस्रं यच्च तद्ब्रह्मणो युगम् ॥ सवनं युगसाहस्रं ब्रह्मणः पद्मजन्मनः ॥ २० ॥
Eight thousand Brahmā years make one Brahmā Yuga. A thousand Brahmā Yugas make one Savana of Brahmā.
english translation
varSANAmaSTasAhasraM yacca tadbrahmaNo yugam ॥ savanaM yugasAhasraM brahmaNaH padmajanmanaH ॥ 20 ॥
hk transliteration by Sanscript