↑Wilson, William André Auquier. 2007. Guinea Languages of the Atlantic group: description and internal classification. (Schriften zur Afrikanistik, 12.) Frankfurt am Main: Peter Lang.
↑Güldemann, Tom (2018). "Historical linguistics and genealogical language classification in Africa". In Güldemann, Tom (ed.). The Languages and Linguistics of Africa. The World of Linguistics series. Vol.11. Berlin: De Gruyter Mouton. pp.58–444. doi:10.1515/9783110421668-002. ISBN978-3-11-042606-9.