Determination of a time- and space-dependent heat flux relaxation function by means of a restricted Dirichlet-to-Neumann operatorJanno, JaanMathematical methods in the applied sciences2004 / p. 1241-1260 https://www.researchgate.net/publication/229807515_Determination_of_a_time-_and_space-dependent_heat_flux_relaxation_function_by_means_of_a_restricted_Dirichlet-to-Neumann_operator