Srimad-Bhagavatam: Canto 9 - Chapter 1 - Verse 35
Sanskrit:
तवेमे तनयास्तात जनमेजयपूर्वका: ।श्रुतसेनो भीमसेन उग्रसेनश्च वीर्यवान् ॥ ३५ ॥
ITRANS:
taveme tanayās tātajanamejaya-pūrvakāḥśrutaseno bhīmasenaugrasenaś ca vīryavān
Translation:
My dear King, your four sons — Janamejaya, Śrutasena, Bhīmasena and Ugrasena — are very powerful. Janamejaya is the eldest.