@misc{indiciae1e20d1216a40,
  title = {Oblique map showing maximum extent of 20,000-year-old (Tioga) glaciers, Yosemite National Park, central Sierra Nevada, California},
  author = {T. R. Alpha and Clyde Wahrhaftig and N.K. Huber},
  year = {1987},
  doi = {10.3133/i1885},
  url = {https://pubs.usgs.gov/publication/i1885},
  note = {Source identifier: i1885}
}