Srimad-Bhagavatam: Canto 12 - Chapter 1 - Verse 22
Sanskrit:
एवंलक्षणलक्ष्याणि पुराणानि पुराविद: ।मुनयोऽष्टादश प्राहु: क्षुल्लकानि महान्ति च ॥ २२ ॥
ITRANS:
evaṁ lakṣaṇa-lakṣyāṇipurāṇāni purā-vidaḥmunayo ’ṣṭādaśa prāhuḥkṣullakāni mahānti ca
Translation:
Sages expert in ancient histories have declared that the Purāṇas, according to their various characteristics, can be divided into eighteen major Purāṇas and eighteen secondary Purāṇas.