U.S. Energy Information Administration(September 2015)/Technically Recoverable Shale Oil and Shale Gas Resources: An Assessment of 137 Shale Formations in 41 Countries Outside the United States/Technically Recoverable Shale Oil and Shale Gas Resources: South Africa
Petroleum Agency South Africa/ Exploration Maps: South Africa / Petroleum Exploration and Production Activities in South Africa / David van der Spuy. Natural gas in South Africa – production and exploration