@article{1151,
  author = {Justin Werfel and Radhika Nagpal},
  title = {Extended Stigmergy in Collective Construction},
  year = {2006},
  journal = {IEEE Intelligent Systems},
  volume = {21},
  pages = {20-28},
  url = {https://ssr.seas.harvard.edu/files/ssr/files/ieeeis06-werfel.pdf},
  language = {eng},
}