@misc{indiciaeb8a22302a163,
  title = {P300 and anticipated task difficulty.},
  author = {P Ullsperger and U Neumann and H G Gille and M Pietschmann},
  year = {1987},
  doi = {10.1016/0167-8760(87)90018-3},
  url = {https://pubmed.ncbi.nlm.nih.gov/3610730/},
  note = {Source identifier: 3610730}
}