1. Aczél, J.,Vorlesungen über Funktionalgleichungen und ihre Anwendungen. Birkhäuser, Basel, 1961.
2. Aczél, J. andDaróczy, Z.,On measures of information and their characterizations. Academic Press, New York-London, 1975.
3. Butzer, P. L.,A survey of the Whittaker-Shannon sampling theorem and some of its extensions. J. Math. Res. Exposition3 (1983), 185–212.
4. Butzer, P. L. andNessel, R. J.,Fourier analysis and approximation. Birkhäuser, Basel; Academic Press, New York, 1971.
5. Butzer, P. L. andStens, R. L.,The Poisson summation formula, Whittaker's cardinal series and approximate integration. InProc. Second Edmonton Conf. on Approximation Theory (Edmonton, Canada, June 1982), Amer. Math. Soc., Providence, R.I., 1983, pp. 19–36.