Garudapurana 1.87.30

1.87.30

ādityā vasavaḥ sādhyāgaṇā dvādaśakāstrayaḥ /
ekādaśā tathā rudrā vasavo 'ṣṭau prakīrtitāḥ //

the Ādityas, Vasus, and Sādhyas are three groups of twelve;
the Rudras are declared as eleven, and the Vasus as eight;