Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, (Ed.) (2017). "Urdu". Glottolog 3.0. Jena, Germany: Max Planck Institute for the Science of Human History.
"NIST 2007 Language Recognition Evaluation"(PDF). Alvin F. Martin, Audrey N. Le. Speech Group, Information Access Division, Information Technology Laboratory National Institute of Standards and Technology, USA. 1 July 2016 tarihinde kaynağından(PDF) arşivlendi. Erişim tarihi: 7 March 2019.
"NIST 2007 Language Recognition Evaluation"(PDF). Alvin F. Martin, Audrey N. Le. Speech Group, Information Access Division, Information Technology Laboratory National Institute of Standards and Technology, USA. 1 July 2016 tarihinde kaynağından(PDF) arşivlendi. Erişim tarihi: 7 March 2019.