Natyashastra
द्विप्रकारनिवृत्तश्च त्र्यंशोऽथ त्रिविधस्तथा । त्र्यस्रश्च चतुरस्रश्च मिश्रश्चापि प्रकीर्तितः ॥ २५४॥
There are two kinds of conclusions, each consisting of three parts. These are declared to be of three types — Tryasra (triple time), Caturasra (quadruple time), and Miśra (mixed time).
english translation
dviprakAranivRttazca tryaMzo'tha trividhastathA । tryasrazca caturasrazca mizrazcApi prakIrtitaH ॥ 254॥
hk transliteration by Sanscript