@misc{indiciae64bd607c3495,
  title = {Specification for the U.S. Geological Survey Historical Topographic Map Collection},
  author = {Gregory J. Allord and Jennifer L. Walter and Kristin A. Fishburn and Gale A. Shea},
  year = {2014},
  doi = {10.3133/tm11b6},
  url = {https://pubs.usgs.gov/publication/tm11B6},
  note = {Source identifier: tm11B6}
}