Hansen, K. 1981. THE MINERAL RESOURCES POTENTIAL OF THE EARTH: Proceedings of the 2. international symposium in Hannover at the federal Institute for Geosciences and mineral Resources, April 18-20, 1979. Ed. F. Bender. Stuttgart 1979, V, 156 s., ill., 24 cm. Pris ikke oplyst. E. Schweizerbart1 sehe Verlagsbuchh. Geografisk Tidsskrift. 81, (jan. 1981).