Spooner, Brian (1994). "Dari, Farsi, and Tojiki". In Marashi, Mehdi (ed.). Persian Studies in North America: Studies in Honor of Mohammad Ali Jazayery. Leiden: Brill. pp. 177–178. ISBN9780936347356.
Spooner, Brian (2012). "Dari, Farsi, and Tojiki". In Schiffman, Harold (ed.). Language policy and language conflict in Afghanistan and its neighbors: the changing politics of language choice. Leiden: Brill. p. 94. ISBN978-9004201453.
Campbell, George L.; King, Gareth, eds. (2013). "Persian". Compendium of the World's Languages (3rd ed.). Routledge. p. 1339. ISBN9781136258466.