Shiva Purana
सुरसायास्सहस्रं तु सर्पाणाममितौजसाम् ॥ अनेकशिरसां तेषां खेचराणां महात्मनाम् ॥ ४४ ॥
Surasa and a thousand serpents of immeasurable strength They were great astronauts with many heads.
english translation
surasAyAssahasraM tu sarpANAmamitaujasAm ॥ anekazirasAM teSAM khecarANAM mahAtmanAm ॥ 44 ॥
hk transliteration by Sanscript