Natyashastra
प्राङ्ग्मुखस्तु ततः कुर्यात्पुरुषस्त्रीनपुंसकैः । त्रिपद्या सूत्रभृद्रुद्रब्रह्मोपेन्द्राभिवादनम् ॥ ९६॥
Then, facing east, the Sūtradhāra (Director) should perform salutations to Rudra, Brahmā, and Upendra (Viṣṇu) using the three-footed movement, characterized as masculine, feminine, and neuter.
english translation
prAGgmukhastu tataH kuryAtpuruSastrInapuMsakaiH । tripadyA sUtrabhRdrudrabrahmopendrAbhivAdanam ॥ 96॥
hk transliteration by Sanscript