@misc{indiciae31d88f603017,
  title = {The alpha spending function approach to interim data analyses.},
  author = {D L DeMets and G Lan},
  year = {1995},
  doi = {10.1007/978-1-4615-2009-2\_1},
  url = {https://pubmed.ncbi.nlm.nih.gov/7640159/},
  note = {Source identifier: 7640159}
}