van Donzel, Emeri (1994). Islamic Reference Desk. Brill Academic. s. 461. Iranian term applied to region lying to the northeast of Iran and ultimately indicating very vaguely the country of the Turkic peoples.
Gnoli, Gherardo (1980). Zoroaster's Time and Homeland. Naples: Instituto Univ. Orientale. OCLC07307436. Iranian tribes that also keep on recurring in the Yasht, Airyas, Tuiryas, Sairimas, Sainus and Dahis
