Videvdad
“Of the [Avestan] books listed in the Dēnkard, only the Videvdad is still complete, while others are incomplete or lost.”1
“The Videvdad (or Vendidad ) in twenty-one chapters, Avestan...'the law...for how to keep the evil gods away'...deals mainly with pollution and purification”2
1 Prods O. Skjærvø, The Spirit of Zoroastrianism, The Sacred Literature Series (New Haven [Conn.]: Yale University Press, 2011), 2.