“…For the isotropic case, see, for example, [24,25,28,29,41,46,47,49]. For the anisotropic case in the three-dimensions, one can use the oscillating-decaying solutions to reconstruct unknown obstacles in a given medium, see [34,35,42,43]. It is worth mentioning that for the anisotropic case in the plane, one can also construct CGOs via the quasi-conformal map, and we refer readers to [48] for more detailed discussions.…”