@misc{indiciaece928f8b43ae,
  title = {Sedimentary environments and coal-forming mechanism of the Jurassic Yan'an Formation, Huangling mining area, Ordos Basin, China},
  author = {Tian Ming and Mao Bangzhuo and Liu Shu and Zhang Yonglin and Han Changlin and Bion H. Kent and R.G. Hobbs and E. A. Johnson and W.S. Sigleo},
  year = {1989},
  doi = {10.3133/ofr89180},
  url = {https://pubs.usgs.gov/publication/ofr89180},
  note = {Source identifier: ofr89180}
}