Avestan written transmission
Tools for Avestan Text Criticism
The Exhition The Everlasting Flame (11th october-14th december 2013, Brunei Gallery, SOAS, London) shows a nice sample of Avestan manuscripts usually hosted in the British Library
The text of the Yasna ī Rapihwin ceremony is already available in ADA, vid.
The text of the Wištāsp Yašt ceremony is already available in ADA, vid.
Kurosh Niknam reads a fragment of the Xorde Awesta
Indian priests reciting some fragments of the Avesta
Avestan Digital Archive 2008