1. Alfonso, R.S., 1976. A Géologica de Moçambique. Direçcao dos Servicos de Géologica é Minas, Impresa naçional de Moçambique, Maputo
2. The geochronolgy and signifiance of ash-fall tuffs in the glaciogenic carboniferous-Permian Dwyka Group of Namibia and South Africa;Bangert;Journal of African Earth Sciences,1999
3. The Tuli coal district;Barber,1986
4. The Bubye coal district, Save-Limpopo basin;Barber,1986
5. The Save-Runde coal area, Save-Limpopo basin;Barber,1987