References ========== .. [I] Durbin, T.J., and C. Berenbrock. 1985. Three-dimensional simulation of free-surface aquifers by the finite-element method. U.S. Geological Survey Water-Supply Paper 2270, pp. 51–67. .. [II] Carslaw, H.S., and J.C. Jaeger. 1959. Conduction of heat in solids. 2nd ed. Oxford, UK: Oxford University Press.