From the Analysis ToolPak Help file...
A bibliography of statistical methods and algorithms
The following book provides detailed information about the algorithms used to create the Microsoft Excel analysis tools and functions.
Strum, Robert D., and Donald E. Kirk. First Principles of Discrete Systems and Digital Signal Processing. Reading, Mass.: Addison-Wesley Publishing Company, 1988.
The following books provide detailed information about statistical methods or algorithms used to create the Microsoft Excel statistical tools and functions.
Abramowitz, Milton, and Irene A. Stegun, eds. Handbook of Mathematical Functions, with Formulas, Graphs, and Mathematical Tables. Washington, D.C.: U.S. Government Printing Office, 1972.
Box, George E.P., William G. Hunter, and J. Stuart Hunter. Statistics for Experimenters: An Introduction to Design, Data Analysis, and Model Building. New York: John Wiley and Sons, 1978.
Devore, Jay L. Probability and Statistics for Engineering and the Sciences. 4th ed. Wadsworth Publishing, 1995.
McCall, Robert B. Fundamental Statistics for the Behavioral Sciences. 5th ed. New York: Harcourt Brace Jovanovich, 1990.
Press, William H., Saul A. Teukolsky, William T. Vetterling, and Brian P. Flannery. Numerical Recipes in C: The Art of Scientific Computing. 2nd ed. New York: Cambridge University Press, 1992.
Sokal, Robert R., and F. James Rohlf. Biometry: The Principles and Practice of Statistics in Biological Research. 2nd ed. New York: W. H. Freeman, 1995.