“…The last problems arise from different contexts of applied sciences, e.g., from aquifer analysis. For surveys on the subject, we refer the reader to [4,5,9,13,[16][17][18]22,26,28,31,34,35,40] and the references therein. To our knowledge, Baumeister and Kunisch [5] were the first who investigated the above inverse problem and that for the Dirichlet problem.…”