Natyashastra
ध्रुवासञ्ज्ञानि यानि स्युर्नारदप्रमुखैर्द्विजैः । गीताङ्गानि तु सर्वाणि विनियुक्तान्यनेकशः ॥ १॥
Listen now from me about those types (of songs) which have been called Dhruvās by Brāhmaṇas such as Nārada and others.
english translation
dhruvAsaJjJAni yAni syurnAradapramukhairdvijaiH । gItAGgAni tu sarvANi viniyuktAnyanekazaH ॥ 1॥
hk transliteration by Sanscript