^Hammarström, Harald; Forkel, Robert; Haspelmath, Martin; Bank, Sebastian (编).乌尔都语.Glottolog 2.7. Jena: Max Planck Institute for the Science of Human History. 2016.
Chatterji, Suniti K. (1960).Indo-Aryan and Hindi (rev. 2nd ed.). Calcutta: Firma K.L. Mukhopadhyay.
Dua, Hans R. (1992). Hindi-Urdu as a pluricentric language. In M. G. Clyne (Ed.),Pluricentric languages: Differing norms in different nations. Berlin: Mouton de Gruyter.ISBN3-11-012855-1.
Dua, Hans R. (1994b). Urdu. In Asher (Ed.) (pp. 4863-4864).
Dua, Hans R. (1994a). Hindustani. In Asher (Ed.) (pp. 1554).
Kelkar, A. R. (1968).Studies in Hindi-Urdu: Introduction and word phonology. Poona: Deccan College.
Khan, M. H. (1969). Urdu. In T. A. Sebeok (Ed.),Current trends in linguistics (Vol. 5). The Hague: Mouton.
Narang, G. C.; & Becker, D. A. (1971). Aspiration and nasalization in the generative phonology of Hindi-Urdu.Language,47, 646-767.
Ohala, M. (1972). Topics in Hindi-Urdu phonology. (PhD dissertation, University of California, Los Angeles).
Rai, Amrit. (1984).A house divided: The origin and development of Hindi-Hindustani. Delhi: Oxford University Press.ISBN0-19-561643-X.