@misc{indiciaeb84cee22c362,
  title = {Coal in sub-Saharan-African countries undergoing desertification},
  author = {J. N. Weaver and Michael E. Brownfield and M. J. Bergin},
  year = {1990},
  doi = {10.1016/0899-5362(90)90004-x},
  url = {https://pubs.usgs.gov/publication/70015900},
  note = {Source identifier: 70015900}
}