On Neumann and Poincare problems in mathematical physics
  It is proved the existence of nonclassical solutions of the Neumann and Poincare problems for generalizations of the Laplace equation in anisotropic and nonhomogeneous media in almost smooth domains with arbitrary boundary data that are measureable with respect to logarithmic capacity. Moreover, it is shown that the spaces of such solutions have the infinite dimension. 
A.S. Yefimushkin
math.CV