Natyashastra
द्व्यङ्गं चितप्रवृत्तं वा चैकाङ्गं वापि कीर्तितम् । द्व्यङ्गे व्याससमासाभ्यां ध्रुवाधातुविधिः स्मृतः ॥ २०१॥
The two-limbed form is said to consist of Sthita and Pravṛtta, or it may also be one-limbed. In the two-limbed form, the rules concerning Dhruvās and Dhātus apply both separately and in combination.
english translation
dvyaGgaM citapravRttaM vA caikAGgaM vApi kIrtitam । dvyaGge vyAsasamAsAbhyAM dhruvAdhAtuvidhiH smRtaH ॥ 201॥
hk transliteration by Sanscript