The Avesta of today does not merely consist of the remnants of the Sassanian canon: its nucleus, the liturgical books (the Yasna, the Yashts, and the prayers), goes back to an independent collection with the canon.
- Samuel Nyberg
( "Sasanid Mazdaism according to Moslem Sources", JCOI, 39 (1958), 1-63, p. 23 )
