1. 1. Ahlfors, L. V. (1966). Lectures on quasiconformal mappings. Princeton, N.J.: Van Nostrand. Reprinted by Wadsworth Ink. Belmont, 1987.
2. Quasiconformal Mappings in the Plane
3. The Beltrami Equation
4. Semilinear equations in a plane and quasiconformal mappings
5. 6. Astala, K., Iwaniec, T. & Martin, G. (2009). Elliptic partial differential equations and quasiconformal mappings in the plane. Princeton Mathematical Series. Vol. 48. Princeton, N.J.: Princeton Univ. Press.