ISBN 9782701802725. Jean Kellens, „The Gāthās, Said to Be of Zarathustra” w: Michael Stausberg, Yuhan Sohrab‐Dinshaw Vevaina, Anna Tessmann (red.), „The Wiley Blackwell Companion to Zoroastrianism”, Wiley Blackwell, 2015, s. 44–50. ISBN 9781444331356. Firoze M. Kotwal, Philip G. Kreyenbroek, „Prayer” w: Michael Stausberg, Yuhan Sohrab‐Dinshaw Vevaina, Anna Tessmann (red.), „The Wiley Blackwell Companion to Zoroastrianism”, Wiley Blackwell, 2015, s. 333–344. ISBN 9781444331356. Wolfgang Lentz, „ASHEM VOHU (YASNA 27, 14)” w: J. C. Heesterman , G. H. Schokker , V. I. Subramoniam (red.), „Pratidanam: Indian, Iranian, and Indo-European Studies Presented to Franciscus Bernardus Jacobus Kuiper on His Sixtieth Birthday: 34”, Haga, Paryż, 1968, s. 160–169. Jenny Rose, „Zoroastrianism: An Introduction”, I.B. Tauris, 2011. ISBN 9781848850873. Bernfried Schlerath, AŠƎM VOHŪ, Encyclopedia Iranica.