@misc{indiciae72a022489712,
  title = {Planning a longitudinal study. I. Sample size determination.},
  author = {J J Schlesselman},
  year = {1973},
  doi = {10.1016/0021-9681(73)90060-x},
  url = {https://pubmed.ncbi.nlm.nih.gov/4759580/},
  note = {Source identifier: 4759580}
}