John Harrison Thomas Brennan Steven Gapinski The Gergonne p-pile Problem and the Dynamics of the Function x | => (x + r)/p. 103-113 1998 82 Discrete Applied Mathematics 1-3 http://dx.doi.org/10.1016/S0166-218X(97)00132-7 db/journals/dam/dam82.html#HarrisonBG98