1. Bruss, F.T., Louchard, G., Turner, J.W.: On the
$$N$$
-tower-problem and related problems. Adv. Appl. Probab. 35, 278–294 (2003)
2. Engel, A.: The computer solves the three tower problem. Am. Math. Mon. 100, 62–64 (1993)
3. Ferguson, T.S.: Gambler’s Ruin in Three Dimensions (1995).
http://www.math.ucla.edu/gamblers
4. Finch, S.: Gambler’s Ruin (2008).
http://www.people.fas.harvard.edu/sfinch/csolve/ruin.pdf
5. Grinstead, C.M., Snell, J.L.: Introduction to Probability, 2nd edn. American Mathematical Society, Providence (2006)