{"id":"000028892","type":"book","title":"Background to the Transvaal Iron Age : new discoveries at Olifantspoort and Broederstroom. - Cape Town","container-title":"Journal of the South African Institute of Mining and Metallurgy ; 74.1974, 6 S. : 1 Ill","author":[{"family":"Mason","given":"Ronald J."}],"issued":{"raw":"1974"}}