@misc{indiciaed674433eefd3,
  title = {A guided inquiry approach to learning the geology of the U.S},
  author = {M.L. Leech and D. G. Howell and A.E. Egger},
  year = {2018},
  doi = {10.5408/1089-9995-52.4.368},
  url = {https://pubs.usgs.gov/publication/70026587},
  note = {Source identifier: 70026587}
}