1. Abramowitz, M. andStegun, I. A.,Handbook of mathematical functions. Dover Publications, Inc., New York, 1965.
2. Aigner, M.,Kombinatorik I. Springer-Verlag, Berlin, 1975.
3. Butzer, P. L. andHauss, M.,On Stirling functions of the second kind. Stud. Appl. Math.84 (1991), 71–79.
4. Butzer, P. L. andHauss, M.,Stirling functions of first and second kind; some new applications. To appear in “Approximation, Interpolation and Summability”, (Proc. Conf. in honour of Prof. Jakimovski, Research Inst. of Math. Sciences, Bar Ilan University, Tel Aviv, June 4–8, 1990), Israel Mathematical Conference Proceedings, Vol. 4 (1991), Weizmann Press, Israel, pp. 89–108.
5. Butzer, P. L., Hauss, M. andSchmidt, M.,Factorial functions and Stirling numbers of fractional orders. Resultate Math.16 (1989), 16–48.