@misc{indiciaeb4863acd848d,
  title = {One hundred and sixty years of Grand Canyon geological mapping},
  author = {Karl Karlstrom and Laura Crossey and Peter W. Huntoon and George Billingsley and Michael Timmons and Ryan S. Crow},
  year = {2019},
  url = {https://pubs.usgs.gov/publication/70212617},
  note = {Source identifier: 70212617}
}