@article { 102,
	title = {Extended Stigmergy in Collective Construction},
	journal = {IEEE Intelligent Systems},
	volume = {21},
	number = {2},
	year = {2006},
	pages = {20-28},
	url = {files/ssr/files/ieeeis06-werfel.pdf},
	author = {Werfel, Justin and Radhika Nagpal}
}
