@misc{indiciae61ed4c794cfa,
  title = {Biopotential amplifier for simultaneous operation with biomagnetic instruments.},
  author = {J Virtanen and L Parkkonen and R J Ilmoniemi and E Pekkonen and R Näätänen},
  year = {1997},
  doi = {10.1007/bf02534098},
  url = {https://pubmed.ncbi.nlm.nih.gov/9327620/},
  note = {Source identifier: 9327620}
}