David Beach, M. F. C. Bourdillon, James Denbow, Martin Hall, Paul Lane, Innocent Pikirayi, Gilbert Pwiti, Thomas N. Huffman, Thomas N. Huffman, The South African Archaeological Bulletin, Vol. 52, No. 166 (Dec., 1997), pp. 125-143
No takes yet. Share an insight, caveat, or question.
Beach et al. (1997) studied this question.