h. Birkhauser. [49] Helbing, D., Yu, W. 2008. Migration as a mechanism to promote cooperation. Ad- vances in Complex Systems 11 641 - 652 [50] Her; A.V.M., 1994. Collective phenomena in spatially extended evolutionary games. J. Theor. Biol. 169, 65-87. [51] Hofbauer, J., 1999. The spatially dominant e