Citation: R. Kangro et al., Extendability of solutions of Helmholtz's equation to the interior of a two-dimensional scatterer, Q APPL MATH, 58(3), 2000, pp. 591-600
Citation: U. Kangro et R. Nicolaides, Divergence boundary conditions for vector Helmholtz equations with divergence constraints, RAIRO-M MOD, 33(3), 1999, pp. 479-492