1. The Vryheid Coalfield of northern Natal;Bell,1986
2. Controls on coal distribution;Cadle,1982
3. Depositional framework and control of coal distribution and quality, Van Dyks Drift area, northern Karoo basin;Cairncross,1979
4. Anastomosing river deposits: palaeoenvironmental control on coal quality and distribution, northern Karoo Basin;Cairncross;Trans. Geol. Soc. S. Afr.,1980
5. Depositional environments of the Permian Vryheid Formation in the east Witbank Coalfield; a framework for coal seam stratigraphy, occurrence and distribution;Cairncross,1986