Shiva Purana
तत्रापि मम ते पुत्राश्चत्वारो योगसाधकाः ॥ भविष्यंति महात्मानस्तन्नामानि ब्रुवे विधे॥१८॥
There also four sons will be born of me all aspiring after the Yogic path and noble-souled. O Brahmā, I shall mention their names.
english translation
tatrApi mama te putrAzcatvAro yogasAdhakAH ॥ bhaviSyaMti mahAtmAnastannAmAni bruve vidhe॥18॥
hk transliteration by Sanscript