TY  - JOUR
TI  - Indirect Reciprocity, Image Scoring, and Moral Hazard
UR  - http://dx.doi.org/10.1073/pnas.0407370102
PY  - 2005-01-01
JO  - Proceedings of the National Academy of Sciences (PNAS)
AU  - De Silva, Hannelore 
ER -