Jaiminīya (Talavakāra) Brāhmaṇa 2-3.94

Now this is the Virāj-Svarāj [sacrifice].
Two brothers should sacrifice with this sacrifice,
who should desire: 'May one of us attain kingship, and the other autonomous rule.' It corresponds to the Virāj and the Anuṣṭubh.
For kingship is what the Virāj is;
and autonomous rule is what the Anuṣṭubh is.
With the Virāj the younger attains kingship; with the Anuṣṭubh the elder attains autonomous rule, [that] world.
Its two sāmans are both the Bṛhat and the Rathantara.
For kingship is what the Rathantara is;
and autonomous rule is what the Bṛhat is.
With the Rathantara the younger attains kingship;
with the Bṛhat the elder attains autonomous rule, [that] world.
It has three nine-verse stotras, three fifteen-verse, three seventeen-verse,
[and] three twenty-one-verse.
With the nine-verse ones the younger attains kingship; with the fifteen-verse ones the elder attains autonomous rule, [that] world.
With the seventeen-verse ones the younger attains kingship; with the twenty-one-verse ones the elder attains autonomous rule, [that] world.

Concerning this they say: 'This sacrifice is only for one who has already prospered, not for one wishing to prosper. The stoma is non-procreative, and it corresponds to the Virāj and the Anuṣṭubh.'

And it is fully attained.