TY  - RPRT
TI  - Evolution of cooperation: two for one?
AU  - Martin Ackermann
AU  - Lin Chao
PY  - 2004
DO  - 10.1016/j.cub.2003.12.049
UR  - https://pubmed.ncbi.nlm.nih.gov/14738754/
ID  - 14738754
ER  -