S. West and A. Gardner, “Altruism, Spite and Greenbeards,” Sci 327 (2010): 1341.
564
S. Smukalla et al., “FLO1 Is a Variable Green Beard Gene That Drives Biofilm-like Cooperation in Budding Yeast,” Cell 135 (2008): 726; E. Queller et al., «Single-Gene Greenbeard Effects in the Social Amoeba Dictyostelium discoideum,” Sci 299 (2003): 105.