@misc{indiciaeb619f8bb8db6,
  title = {Low-ash solid fuel from sewage sludge; an acid extraction method (progress report)},
  author = {F. E. Senftle and P. Hackney and F. Jackson and A. Parker and K. Miller and Z. A. Brown},
  year = {1988},
  doi = {10.3133/ofr88239},
  url = {https://pubs.usgs.gov/publication/ofr88239},
  note = {Source identifier: ofr88239}
}