@misc{indiciaebef3f1068afa,
  title = {Identifiability, stratification and minimum variance estimation of causal effects.},
  author = {Xingwei Tong and Zhongguo Zheng and Zhi Geng},
  year = {2005},
  doi = {10.1002/sim.2153},
  url = {https://pubmed.ncbi.nlm.nih.gov/16149123/},
  note = {Source identifier: 16149123}
}