1. Aczél, J.,Lectures on functional equations and their applications. Academic Press, New York—London, 1966.
2. Aczél, J. andDhombres, J.,Functional equations in several variables. Cambridge University Press, Cambridge—New York—New Rochelle—Melbourne—Sydney, 1989.
3. Aczél, J. andHaruki, H.,Commentary to Einar Hille's collected works. The MIT Press, Cambridge, MA—London (edited by R. R. Kallman) (1975), pp. 651–658.
4. Ahlfors, L. V.,Complex analysis, 2nd ed. McGraw-Hill, New York, 1966.
5. Burckel, R. B.,An introduction to classical complex analysis. Vol. 1. Academic Press, New York—San Francisco, 1979.