@misc{indiciaed6535e01a8e8,
  title = {Principles of multilevel modelling.},
  author = {S Greenland},
  year = {2000},
  doi = {10.1093/ije/29.1.158},
  url = {https://pubmed.ncbi.nlm.nih.gov/10750618/},
  note = {Source identifier: 10750618}
}