SB 4.1.37

tasya yakṣa-patir devaḥ
 kuberas tv iḍaviḍā-sutaḥ
rāvaṇaḥ kumbhakarṇaś ca
 tathānyasyāṁ vibhīṣaṇaḥ
Synonyms: 
tasya — his; yakṣa-patiḥ — the king of the Yakṣas; devaḥ — demigod; kuberaḥ — Kuvera; tu — and; iḍaviḍā — of Iḍaviḍā; sutaḥ — son; rāvaṇaḥ — Rāvaṇa; kumbhakarṇaḥ — Kumbhakarṇa; ca — also; tathā — so; anyasyām — in the other; vibhīṣaṇaḥ — Vibhīṣaṇa.
Translation: 
Viśravā had two wives. The first wife was Iḍaviḍā, from whom Kuvera, the master of all Yakṣas, was born, and the next wife was named Keśinī, from whom three sons were born — Rāvaṇa, Kumbhakarṇa and Vibhīṣaṇa.