W. D. Hamilton, “Geometry for the Selfish Herd,” J Theoretical Biol 31 (1971): 295.
568
R. Trivers, “The Evolution of Reciprocal Altruism,” Quarterly Rev of Biol 46 (1971): 35.
569
R. Seyfarth and D. Cheney, “Grooming, Alliances and Reciprocal Altruism in Vervet Monkeys,” Nat 308 (1984): 541.
570
R. Axelrod and W. D. Hamilton, “The Evolution of Cooperation,” Sci 211 (1981): 1390.
571
M. Nowak and K. Sigmund, “Tit for Tat in Heterogeneous Populations,” Nat 355 (1992): 250; R. Boyd, “Mistakes Allow Evolutionary Stability in the Repeated Prisoner’s Dilemma Game,” J Theoretical Biol 136 (1989): 4756.
