Srimad-Bhagavatam: Canto 5 - Chapter 1 - Verse 39
Sanskrit:
तदुपरिष्टाच्चतसृष्वाशास्वात्मयोनिनाखिलजगद्गुरुणाधिनिवेशिता ये द्विरदपतय ऋषभ: पुष्करचूडो वामनोऽपराजित इति सकललोकस्थितिहेतव: ॥ ३९ ॥
ITRANS:
tad-upariṣṭāc catasṛṣv āśāsvātma-yoninākhila-jagad-guruṇādhiniveśitā ye dvirada-pataya ṛṣabhaḥ puṣkaracūḍo vāmano ’parājita iti sakala-loka-sthiti-hetavaḥ.
Translation:
On the top of Lokāloka Mountain are the four gaja-patis, the best of elephants, which were established in the four directions by Lord Brahmā, the supreme spiritual master of the entire universe. The names of those elephants are Ṛṣabha, Puṣkaracūḍa, Vāmana and Aparājita. They are responsible for maintaining the planetary systems of the universe.