On boundary behavior and Dirichlet problem for Beltrami equations
  We show that arbitrary homeomorphic solutions to the Beltrami equations with generalized derivatives satisfy certain moduli inequalities. On this basis, we develope the theory of the boundary behavior of such solutions and prove a series of criteria for the existence of regular, pseudoregular and multi-valued solutions for the Dirichlet problem to the Beltrami equations in arbitrary Jordan domains and in arbitrary finitely connected domains bounded by mutually disjoint Jordan curves, correspondingly. 
Denis Kovtonyuk, Igor Petkov, Vladimir Ryazanov and Ruslan Salimov
math.CV