@inbook{10.2307/j.ctt7sw18.7,
 ISBN = {9780691142753},
 URL = {http://www.jstor.org/stable/j.ctt7sw18.7},
 abstract = {In the previous chapter, we have investigated strategies for playing the Donation game repeatedly againstthe sameco-player. In this chapter, we assume that the same game is played repeatedly, but always againstanotherco-player. Third parties have to return the helpful action. This introduces major differences between direct and indirect reciprocation, as we shall presently see.TheTit for Tatstrategy, which played such a basic role in the previous chapter, discriminates according to the outcome of the previous round. In direct reciprocity, what happens to a player is caused by what the co-player does. But in the context},
 bookauthor = {Karl Sigmund},
 booktitle = {The Calculus of Selfishness:},
 pages = {82--103},
 publisher = {Princeton University Press},
 title = {Indirect Reciprocity: The Role of Reputation},
 year = {2010}
}