Natyashastra
शक्वर्याश्चाति कृत्याश्च येऽन्तरे चावसानिकी । तेषां मात्रार्धविहिता ध्रुवा पादमया स्मृता ॥ २१॥
When the Śakvarī or Atikṛtyā (metres) are used for the concluding section, the Dhruvā composed of pādas is to be arranged with half the number of mātrās of those (metres).
english translation
zakvaryAzcAti kRtyAzca ye'ntare cAvasAnikI । teSAM mAtrArdhavihitA dhruvA pAdamayA smRtA ॥ 21॥
hk transliteration by Sanscript