Birthday paradox/Bibliography

Ehrhard Behrends, The Birthday Paradox.
 * in: Ehrhard Behrends, Five-Minute Mathematics. Chapter 11. pp.37-41. Translated by David Kramer. American Mathematical Society, 2008.
 * German original: Ehrhard Behrends, Fünf Minuten Mathematik. Friedr. Vieweg & Sohn Verlag, Wiesbaden, 2006.