South Africa's strategic minerals: Pieces on a continental chessboard - W.C.J. Van Rensburg and D.A. Pretorius 156 pp, £7.97, Valiant Publishers, Johannesburg, 1977 - de Beer, C. (Elsevier)
http://linkinghub.elsevier.com/retrieve/pii/0301-4207(78)90071-5
Keywords: ZP; Q