@misc{indiciae40a10f93efb8,
  title = {Effect of sewage sludge on nutrient and toxic metal content of soil and selected crops grown on tropical soils},
  author = {Nancy Cavallaro and Jose A. Villarrubia},
  year = {1989},
  doi = {10.3133/25213},
  url = {https://pubs.usgs.gov/publication/25213},
  note = {Source identifier: 25213}
}