Natyashastra
एवमेतत्सविस्तारं कथितं परिमाणकम् । चत्वारस्तु गुणा युग्मे ओजे षट्परिकीर्तिताः ॥ १०२॥
Thus I have described the extent and measurement ॥ of the Upavahana॥. In the Caturasra (yugma) there are four gaṇas, and in the Tryasra (oja) there are six gaṇas.
english translation
evametatsavistAraM kathitaM parimANakam । catvArastu guNA yugme oje SaTparikIrtitAH ॥ 102॥
hk transliteration by Sanscript