Natyashastra
अन्यूनायां कलायां तु ध्रुवं प्राज्ञो निवेदयेत् । अथ तालाक्षरवशास्त्वेषां ये तांश्च (वशाच्छेषानन्तांश्च) योजयेत् ॥ १५३॥
In a deficient Kalā, the wise should apply the Dhruva Tāla. Then, according to the strength or weakness of the remaining syllables, they should combine the appropriate Tālas and syllables.
english translation
anyUnAyAM kalAyAM tu dhruvaM prAjJo nivedayet । atha tAlAkSaravazAstveSAM ye tAMzca (vazAccheSAnantAMzca) yojayet ॥ 153॥
hk transliteration by Sanscript