1. National Archives and Records Administration (NARA) 2022 Cartographic and Architectural Records Aerial Photography Collection. Electronic document, https://www.archives.gov/research/cartographic/aerial-photography, accessed 4 February 2022.
2. Library of Congress 2020 Sanborn Map Collection. Electronic document, https://www.loc.gov/collections/sanborn-maps, accessed November 17, 2021.
3. USDA 2022 Aerial Photography Field Office. Electronic document, https://www.fsa.usda.gov/programs-and-services/aerial-photography/index, accessed February 4, 2022.