@article {311216,
	title = {How chimpanzees cooperate in a competitive world},
	year = {2016},
	month = {2016/08/22},
	doi = {    10.1073/pnas.1611826113},
	url = {http://www.pnas.org/content/early/2016/08/16/1611826113},
	author = {Suchak, Malini and Eppley, Timothy M. and Campbell, Matthew W. and Feldman, Rebecca A. and Quarles, Luke F. and de Waal, Frans B. M.}
}
