Shiva Purana
ऊर्जायां तु वसिष्ठस्य पुत्रा वै सप्त जज्ञिरे ॥ ज्यायसी च स्वसा तेषां पुंडरीका सुमध्यमा ॥ ३३ ॥
Vasiṣṭha had seven sons by his wife Śrī Śrīmad-Bhāgavatam. Their sister Jāyasi was very beautiful and had a beautiful waist called Puṇḍarīka.
english translation
UrjAyAM tu vasiSThasya putrA vai sapta jajJire ॥ jyAyasI ca svasA teSAM puMDarIkA sumadhyamA ॥ 33 ॥
hk transliteration by Sanscript