1. Ashanti Goldfields Corporation monthly returns, obtained from the Mines Department of Ghana,1995
2. Studies on the Recovery of Noble Metals from Carbonaceous Ore Concentrates Containing Arsenopyrite and Pyrite;Asiam,1988
3. The hidden layer problem;Green;Geophys. Prospecting,1962
4. Nomograms for determining maximum errors and limiting conditions in seismic refraction surveys with a blind zone problem;Hawkins;Geophys. Prospecting,1961
5. Geophysical Exploration;Heiland,1963