TY - JOUR AU - Muñoz, Vicente PY - 2012 SN - 1027-488X UR - https://hdl.handle.net/20.500.14352/43756 T2 - European Mathematical Society. Newsletter LA - eng M2 - 55 PB - Team TI - The ultimate challenge: the 3x+1 problem [book review] TY - journal article VL - 83 ER -