Natyashastra
वलिता च निवृत्ता च ग्रीवा नवविधार्थतः । समा स्वाभाविकी ध्यानस्वभाजपकर्मसु ॥ १७२॥
Valitā and Nivṛttā are also included, making the neck movements ninefold in total. Samā is natural and is used in meditation, a neutral stance, and the recitation of mantras.
english translation
valitA ca nivRttA ca grIvA navavidhArthataH । samA svAbhAvikI dhyAnasvabhAjapakarmasu ॥ 172॥
hk transliteration by Sanscript