@article{ayres2001strong,
  title = {Strong versus Weak Sustainability: Economics, Natural Sciences, and Consilience}
  author = {Ayres, Robert and van den Berrgh, Jeroen and Gowdy, John and , },
  journal = {Environmental Ethics},
  url = {http://www.pdcnet.org/oom/service?url_ver=Z39.88-2004&rft_val_fmt=&rft.imuse_id=enviroethics_2001_0023_0002_0155_0168&svc_id=info:www.pdcnet.org/collection},
  year = {2001}
}