5Baunsgaard, Thomas, 2001, "A Primer on Mineral Taxation", IMF Working Paper WP/01/139.
6Boadway, Robin and Michael Keen, 2010, "Theoretical Perspectives on Resource Tax Design", in Philip Daniel, Michael Keen and Charles McPherson (eds)? The Taxation of Petroleum and Minerals: Principles, Problems and?Practice. Routledge.