Theological Questions in an Oral Tradition: the Case of Zoroastrianism (Götterbilder, Gottesbilder, Weltbilder: Polytheismus und Monotheismus in der Welt der Antike. Ed.: Reinhard G. Kratz/Hermman Spieckermann. Vol. 1. Tübingen: Mohr Siebeck, 2006. 199-222) - Kreyenbroek, Philip G. (Teachers and teachings in the good religion, 2013)