@misc{indiciaef2f8c4f49288,
  title = {A recommended method for soiling index surveys by automatic filter paper sampler.},
  author = {C E SCHUMANN and C W GRUBER},
  year = {1960},
  doi = {10.1080/00022470.1960.10467954},
  url = {https://pubmed.ncbi.nlm.nih.gov/13748970/},
  note = {Source identifier: 13748970}
}