“…Compared to the classical methods of CGO solutions for complete boundary data [26], the Riemann-Lebesgue lemma plays an important role in [13] to eliminate the redundant Fourier modes produced by reflection, which should be sharpened to a quantitative version when deriving stability estimates. Various quantitative results have been obtained, depending on different a-priori assumptions on the potential functions, see [11] and [24]. In particular, functions in H s (R n ), 0 ≤ s < 1, are considered in [24] and estimates are derived using mollification.…”