1. ERDA Hot dry rock assessment panel, Rep. No. 1, 77–74, 44 (ERDA, 1977).
2. Cummings, R. G., Morris, G. E., Tester, J. W. & Bivins, R. L. Los Alamos Tech. Rep. LA-UR-78-1374 (1978).
3. Harlow, F. H. & Pracht, W. E. J. geophys. Res. 77, 7038 (1972).
4. Garnish, J. Department of Energy Res. Paper No. 9 (London, HMSO, 1976).
5. Tammemagi, H. Y. & Wheildon, J. Geophys J. R. astr. Soc. 38, 83 (1974).