Prasthanatrayi
Prasthanatrayi (Sanskrit: प्रस्थानत्रयी, IAST: Prasthānatrayī), literally, three sources (or axioms), refers to the three canonical texts of theology having epistemic authority, especially of the Vedanta schools. It consists of: The Upanishads, known as Upadeśa Prasthānam (injunctive texts), and the Śruti Prasthānam (the starting point or axiom of revelation), especially the Principal Upanishads.