@misc{indiciae1471ad8ec1f1,
  title = {Experiments versus quasi-experiments: do they yield the same answer?},
  author = {W R Shadish and D T Heinsman},
  year = {1997},
  url = {https://pubmed.ncbi.nlm.nih.gov/9154256/},
  note = {Source identifier: 9154256}
}