Gunnink, Hilde; Sands, Bonny; Pakendorf, Brigitte; Bostoen, Koen (1 December 2015). "Prehistoric language contact in the Kavango-Zambezi transfrontier area: Khoisan influence on southwestern Bantu languages". Journal of African Languages and Linguistics. 36 (2): 193–232. doi:10.1515/jall-2015-0009. hdl:1854/LU-7005944.
Gunnink, Hilde; Sands, Bonny; Pakendorf, Brigitte; Bostoen, Koen (1 December 2015). "Prehistoric language contact in the Kavango-Zambezi transfrontier area: Khoisan influence on southwestern Bantu languages". Journal of African Languages and Linguistics. 36 (2): 193–232. doi:10.1515/jall-2015-0009. hdl:1854/LU-7005944.