1. Golizen, G. M.,The Geometrical Theory of Complex Variables, National Science and Technology Press (1952). (in Russian)
2. Bekua, I. N.,A New Solving Method for Elliptic Differential Equation, National Science and Technology Press (1948). (in Russian)
3. Muskhelishvili, N. I.,Singular Integral Equations, The Academic Press (1962). (in Russian)
4. Gilbert, R. P.,Function Theoretic Methods in Partial Differential Equation, The Academic Press (1969).
5. Lu Jian-kc,The Boundary Value Problems of Analytic Function, Shanghai Science and Technology Press (1987). (in Chinese)