Śatapatha Brāhmaṇa ("of a hundred paths") 13.5.4.20

13.5.4.20

tasya vidhā caturviṃśāḥ pavamānāḥ trivṛdabhyāvartam catuścatvāriṃśāḥ pavamānā ekviṃśānyājyāni triṇavānyukthānyekaviṃśāni pṛṣṭhāni ṣaṭtriṃśāḥ pavamānāstrayastriṃśamabhyāvartamāgniṣṭomasāmādekaviṃśānyukthānyekaviṃśaḥ ṣoḍaśī pañcadaśī rātristrivṛtsandhiḥ

The mode (of chanting) for this (Govinata form) is:--the Pavamâna (stotras) in the Katurvimsa (stoma), and (those chanted) by repetitions in the Trivrit;--the Pavamânas in the Katuskatvârimsa, the Âgya (stotras) in the Ekavimsa, the Ukthas In the Trinava, the Prishthas in the Ekavimsa;--the Pavamânas in the Shattrimsa (36-versed), and (those chanted) by repetitions in the Trayastrimsa (33) up to the Agnishtoma-sâman, the Ukthas in the Ekavimsa, the Shodasin in the Ekavimsa, the night (stotras) in the Pañkadasa, and the Sandhi (stotra) in the Trivrit.