@misc{indiciaecc2c2d69072f,
  title = {Sufficient challenge.},
  author = {H F Smyth},
  year = {1967},
  doi = {10.1016/s0015-6264(67)82886-4},
  url = {https://pubmed.ncbi.nlm.nih.gov/6029673/},
  note = {Source identifier: 6029673}
}