Bundahišn (Primal Creation), the name taken from the opening of the younger Indian recension;
or Zand-āgāhīh (Knowledge from the Zand), the name taken from the opening of the older Iranian one.
Eighth/Ninth Century AD in its main chapters, the later chapters several centuries younger; drawing upon the Sasanian Zand.
Two recensions: the Greater or Iranian, thirty-six chapters, the older and fuller; and the Indian or Lesser, thirty:
Anklesaria, Behramgore Tehmuras, tr. Zand-Ākāsīh: Iranian or Greater Bundahišn. Transliteration and Translation in English. Bombay: Published for Rahnumae Mazdayasnan Sabha by Dastur Framroze A Bode, 1956. Digital edition by Joseph H Peterson, 2002.
https://www.avesta.org/mp/grb.htm.
West, Edward William, tr. “The Bundahis” in Pahlavi Texts, Part I. Sacred Books of the East V. Oxford: Clarendon Press, 1880; reprinted Delhi, 1965.
https://www.avesta.org/mp/bundahis.html.