Srimad-Bhagavatam: Canto 9 - Chapter 1 - Verse 6
Sanskrit:
ऋतेयो रन्तिनावोऽभूत् त्रयस्तस्यात्मजा नृप ।सुमतिर्ध्रुवोऽप्रतिरथ: कण्वोऽप्रतिरथात्मज: ॥ ६ ॥
ITRANS:
ṛteyo rantināvo ’bhūttrayas tasyātmajā nṛpasumatir dhruvo ’pratirathaḥkaṇvo ’pratirathātmajaḥ
Translation:
Ṛteyu had a son named Rantināva, who had three sons, named Sumati, Dhruva and Apratiratha. Apratiratha had only one son, whose name was Kaṇva.