@article{Baldassarri2011,
author = {Baldassarri, D. and Grossman, G.},
title= {Centralized sanctioning and legitimate authority promote cooperation in humans},
year = {2011},
doi = {10.1073/pnas.1105456108},
journal = {Proceedings of the National Academy of Sciences},
volume = {108},
number = {27},
pages = {11023--11027},
}