@misc{indiciae80b55dac14ba,
  title = {A comparison of group sequential methods for binary longitudinal data.},
  author = {Bart Spiessens and Emmanuel Lesaffre and Geert Verbeke},
  year = {2003},
  doi = {10.1002/sim.1361},
  url = {https://pubmed.ncbi.nlm.nih.gov/12590410/},
  note = {Source identifier: 12590410}
}