1. Berkowitz, L., Macaulay, J.: Altruism and Helping Behavior: Social Psychological Studies of Some Antecedents and Consequences. Academic Press, New York (1970)
2. Buchanan, D., Huczynski, A.: Organisational Behaviour: An Introductory Text. Prentice-Hall, Pearson Education (1997)
3. Dawkins, R.: The Selfish Gene. Oxford University Press, Oxford (1976)
4. Lecture Notes in Artificial Intelligence;D. Hales,2003
5. Lecture Notes in Artificial Intelligence;D. Hales,2004