@misc{indiciae2d922518b561,
  title = {Random versus nonrandom assignment in controlled experiments: do you get the same answer?},
  author = {W R Shadish and K Ragsdale},
  year = {1996},
  url = {https://pubmed.ncbi.nlm.nih.gov/8991316/},
  note = {Source identifier: 8991316}
}