Srimad Bhagavatam Canto 04, Chapter 10, Text 02

SB 4.10.2

ilayam api bharyayam
vayoh putryam maha-balah
putram utkala-namanam
yosid-ratnam ajijanat
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The greatly powerful Dhruva Maharaja had another wife, named Ila, who was the daughter of the demigod Vayu. By her he begot a son named Utkala and a very beautiful daughter.
Srimad Bhagavatam Canto 04, Chapter 10, Text 01
Srimad Bhagavatam Canto 04, Chapter 10, Text 03