Natyashastra
एवमेककलो ज्ञेयः कलायोगस्तु भद्रके । गुरुविश्लेषपादेन द्विकलं परिकीर्तितम् ॥ २१९॥
Thus, one Kalā is to be known, and the combination of Kalās in the Bhadraka is to be performed; with the Guru-varṇa at the foot, it is said to be two Kalās.
english translation
evamekakalo jJeyaH kalAyogastu bhadrake । guruvizleSapAdena dvikalaM parikIrtitam ॥ 219॥
hk transliteration by Sanscript