Alles, EJ; Van Dongen, KWA; (2011) Perfectly matched layers for frequency-domain integral equation acoustic scattering problems. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control , 58 (5) pp. 1077-1086. 10.1109/TUFFC.2011.1908 <https://doi.org/10.1109/TUFFC.2011.1908>. Green open access