Johnston, H. H. (1897) British Central Africa.
Last, J. T. (1885) Polyglotta africana orientalis. London: SPCK. Reprinted Leipzig: Zentralantiquariat der DDR.
Madan, A. C. (1906) Wisa handbook. Oxford: Clarendon Press., 136 p.
Madan, A. C. (1913) Lala-Lamba-Wisa and English, English and Lala-Lamba-Wisa dictionary. Oxford: Clarendon Press., c. 300 p.