Giovanni Amelino-Camelia, "Doubly-Special Relativity: First Results and Key Open Problems." Int. J. Mod. Phys. D11 (2002) 1643. Online copy at http://arxiv.org/abs/gr-qc/0210063
... and Europe but not in the United States.
However, because the GBA has no region lockout, European games will work fine on a U.S. GBA unit, and apparently, even a player ...