Natyashastra
उल्लोप्यके तथा शाखा सोत्तरो साम्परान्तके । प्रतिशाख्या तथा चैव सवर्णान्यपदा स्मृताः ॥ २११॥
In the Ullopyaka, as also in the Śākhā, Uttara, and Aparāntaka, and in the Pratiśākhā as well, all the Varṇas of the other limbs are considered equal.
english translation
ullopyake tathA zAkhA sottaro sAmparAntake । pratizAkhyA tathA caiva savarNAnyapadA smRtAH ॥ 211॥
hk transliteration by Sanscript