Computation of volume potentials over bounded domains via approximate   approximations
  We obtain cubature formulas of volume potentials over bounded domains combining the basis functions introduced in the theory of approximate approximations with their integration over the tangential-halfspace. Then the computation is reduced to the quadrature of one dimensional integrals over the halfline. We conclude the paper providing numerical tests which show that these formulas give very accurate approximations and confirm the predicted order of convergence. 
F. Lanzara, V. Maz'ya, G. Schmidt
math.NA