Positive-energy D-bar method for acoustic tomography : a computational studyde Hoop, M. V.; Lassas, Matti; Santacesaria, M.; Siltanen, Samuli; Tamminen, Janne Pertti OlaviInverse problems2016 / art, 025003, p. 1-35 : ill http://dx.doi.org/10.1088/0266-5611/32/2/025003