TY  - JOUR
TI  - Via freedom to coercion: the emergence of costly punishment
SP  - 1905
EP  - 1907
UR  - http://www.sciencemag.org/cgi/content/abstract/316/5833/1905?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=via+freedom+to+coercion&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT
PY  - 2007-08-01
JO  - Science
AU  - Hauert, Christoph 
AU  - Traulsen, Arne  
AU  - De Silva, Hannelore 
AU  - Sigmund, Karl 
AU  - Nowak, Martin A. 
ER -