Natyashastra
पुनश्चिन्तान्विते चैव गतिः कार्या चतुष्कला । अस्वस्थकामिते चैव भये वित्रासिते तथा ॥ ३६॥
Again, in anxiety and restlessness, the gait should be of four Kalās, and likewise in fear and terror.
english translation
punazcintAnvite caiva gatiH kAryA catuSkalA । asvasthakAmite caiva bhaye vitrAsite tathA ॥ 36॥
hk transliteration by Sanscript