Simons, Gary F.; Fennig, Charles D., eds. (2018). "Nobiin". Ethnologue: Languages of the World (Twenty-first ed.). Dallas, Texas. Retrieved 2018-06-06.
glottolog.org
Nordhoff, Sebastian; Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, eds. (2013). "Nobiin". Glottolog 2.2. Leipzig: Max Planck Institute for Evolutionary Anthropology. {{cite book}}: Invalid |display-editors=4 (help)