1. Bergman, S., “The kernel function and conformal mapping”,Amer. Math. Soc. Survey, New York, 1950.
2. Bergman, S. and Schiffer, M.,Kernel functions in mathematical physics, Academic Press, New York, 1953.
3. Carathéodory, C.,Conformal representation, Cambridge, 1952.
4. Courant, R. and Hilbert, D.,Methoden der mathematischen Physik, New York, 1943.
5. Evans, G. C., “Continua of minimum capacity”,Bull. Amer. Math. Soc. Vol. 47 (1941), pp. 717–733.