スキタイ語
↑ Hammarström, Harald; Forkel, Robert; Haspelmath, Martin et al., eds (2016). “Old Ossetic”. Glottolog 2.7. Jena: Max Planck Institute for the Science of Human History. http://glottolog.org/resource/languoid/id/oldo1234
↑ Mallory, J. P.; Adams, Douglas Q. (2006), The Oxford introduction to Proto-Indo-European and the Proto-Indo-European world, Oxford University Press, ISBN 0199287910