@misc{indiciaeef87f1a23c3a,
  title = {Filter sampling method for atmospheric sulfur dioxide at background concentrations.},
  author = {H D Axelrod and S G Hansen},
  year = {1975},
  doi = {10.1021/ac60364a009},
  url = {https://pubmed.ncbi.nlm.nih.gov/1190487/},
  note = {Source identifier: 1190487}
}