19501951-yillarda AQSHning Indiana Universiteti tarixchi olimlari tadqiqotlariga ko'ra eftaliylar [[Eroniy xalqlar]]<nowiki/>ga oid qabila bo'lgan.<ref>{{Kitob manbasi|title="Asia Major, volume 4, part 1". Institute of History and Philology of the Academia Sinica, University of Indiana. 1954. Retrieved 19 August 2017.}}</ref> Buni olim '''Dénes Zsinór'''<ref>{{Kitob manbasi|title=Sinor, Denis (1990). "The establishment and dissolution of the Türk empire". The Cambridge History of Early Inner Asia, volume 1. Cambridge University Press. p. 300. ISBN 978-0-521-24304-9. Retrieved 19 August 2017.}}</ref>''',''' yapon olimi Kazuo Enoki ham o'z ilmiy asarlarida tasdiqlagan.<ref>{{Kitob manbasi|title=Enoki, K. (1959). "On the Nationality of Ephthalites". Memoirs of the Research Department of the Toyo Bunko (PDF). Vol. 18. Tokyo. pp. 1–58. Retrieved 1 April 2017. Internet Archive copy}}</ref>
Etyen De la Vayssier va boshqa olimlar eftaliylar asli turkiy bo‘lib, keyinchalik baqtriya tilini dastlab ma’muriy maqsadlarda, ehtimol keyinroq ona tili sifatida qabul qilgan, degan fikrni ilgari suradilar. {{sfn|de la Vaissière|2012|p=[https://books.google.com/books?id=KZNoAgAAQBAJ&pg=PA146 146]}}.<ref name="HB2020">{{cite book |last1=Bakker |first1=Hans T. |title=The Alkhan: A Hunnic People in South Asia |date=12 March 2020 |publisher=Barkhuis |isbn=978-94-93194-00-7 |page=13, note 17 |url=https://books.google.com/books?id=ZLnVDwAAQBAJ&pg=PA13}}</ref>
