Boyd, James W.; et al. (1979), "Is Zoroastrianism Dualistic or Monotheistic?", Journal of the American Academy of Religion, Vol. XLVII (4): 557–588, doi:10.1093/jaarel/XLVII.4.557, ISSN0002-7189{{citation}}: |volume= has extra text (help)
Boyd, James W.; et al. (1979), "Is Zoroastrianism Dualistic or Monotheistic?", Journal of the American Academy of Religion, Vol. XLVII (4): 557–588, doi:10.1093/jaarel/XLVII.4.557, ISSN0002-7189{{citation}}: |volume= has extra text (help)