@misc{indiciae7c0b89740ed6,
  title = {Mineralogy and geochemistry of a superhigh-organic-sulfur coal, Yanshan Coalfield, Yunnan, China: Evidence for a volcanic ash component and influence by submarine exhalation},
  author = {S. Dai and D. Ren and Y. Zhou and C. L. Chou and X. Wang and L. Zhao and Xudong Zhu},
  year = {2008},
  doi = {10.1016/j.chemgeo.2008.06.030},
  url = {https://pubs.usgs.gov/publication/70000058},
  note = {Source identifier: 70000058}
}