@misc{indiciaec53080bd64aa,
  title = {Cluster randomization: a trap for the unwary.},
  author = {M Underwood and A Barnett and S Hajioff},
  year = {1998},
  url = {https://pubmed.ncbi.nlm.nih.gov/9624757/},
  note = {Source identifier: 9624757}
}