@misc{indiciae50a16ce3e521,
  title = {Contributions to economic geology, 1920, Part II, Mineral fuels--The Lance Creek oil and gas field, Niobrara County, Wyoming},
  author = {E.T. Hancock},
  year = {1921},
  doi = {10.3133/b716e},
  url = {https://pubs.usgs.gov/publication/b716E},
  note = {Source identifier: b716E}
}