@misc{indiciae7c2ac407152f,
  title = {Letter: When is a null cell null?},
  author = {P M Zeltzer},
  year = {1976},
  doi = {10.1016/s0022-3476(76)80510-0},
  url = {https://pubmed.ncbi.nlm.nih.gov/1084919/},
  note = {Source identifier: 1084919}
}