@article{obrien1996social,
  title = {Social and environmental life cycle assessment (SELCA): Approach and methodological development}
  author = {O’Brien, Martin and Doig, Alison and Clift, Roland},
  journal = {The International Journal of Life Cycle Assessment},
  url = {http://link.springer.com/10.1007/BF02978703},
  year = {1996}
}