@misc{indiciaef671233a4cf7,
  title = {Origin and significance of high nickel and chromium concentrations in pliocene lignite of the Kosovo Basin, Serbia},
  author = {L. Ruppert and R. Finkelman and E. Boti and M. Milosavljevic and S. Tewalt and N. Simon and F. Dulong},
  year = {1996},
  doi = {10.1016/0166-5162(95)00031-3},
  url = {https://pubs.usgs.gov/publication/70018409},
  note = {Source identifier: 70018409}
}