@article{externalvalidityfromdocalculusto,
  title = {External Validity: From Do-Calculus to Transportability Across Populations},
  author = {Judea Pearl and Elias Bareinboim},
  year = {2015},
  eprint = {1503.01603},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1503.01603v1},
}