Roberson, Debi; Davidoff, Jules B.; Davies, Ian and Shapiro, L.. 2006. Colour categories and category acquisition in Himba and English. In: Nicola Pitchford and Carole P. Biggam, eds. Progress in Colour Studies. Amsterdam: John Benjamins Publishing Company, pp. 159-172. ISBN 9027232407 [Book Section]

Davidoff, Jules B.; Davies, I.; Roberson, D. and Shapiro, L.. 2002. The development of color categories in two languages: a longitudinal study. Journal of Experimental Psychology General, 133(4), pp. 554-571. ISSN 00963445 [Article]