@article {310462,
	title = {Manufacture and use of tools in wild Sumatran orangutans},
	journal = {Naturwissenschaften},
	volume = {83},
	year = {1996},
	month = {1996},
	pages = {186 - 188},
	isbn = {1432-1904},
	url = {http://dx.doi.org/10.1007/BF01143062},
	author = {van Schaik, C. P. and Fox, E. A. and Sitompul, A. F.}
}
