อ้างอิง ของ ภูเขารัชมอร์

  1. ↑ "Park Statistics". National Park Service. สืบค้นเมื่อ January 23, 2018.
  2. ↑ Mount Rushmore National Memorial. December 6, 2005.60 SD Web Traveler, Inc. Retrieved April 7, 2006.
  3. ↑ McGeveran, William A. Jr. et al. (2004). The World Almanac and Book of Facts 2004. New York: World Almanac Education Group, Inc. ISBN 0-88687-910-8.
  4. ↑ Mount Rushmore, South Dakota (November 1, 2004). Peakbagger.com. Retrieved March 13, 2006.
  5. ↑ Penn & Teller: Bullshit!, episode 5x08 "Mount Rushmore", May 10, 2007
  6. ↑ "Making Mount Rushmore | Mount Rushmore". Oh, Ranger!. Retrieved October 31, 2012.
  7. ↑ "Biography:Senator Peter Norbeck". American Experience: Mount Rushmore. PBS. Retrieved 20 July 2013.
  8. ↑ "Honeycombing process explained from". nps.gov. June 14, 2004. Archived from the original on August 1, 2008. Retrieved March 20, 2010.
  9. ↑ "Geology Fieldnotes". nps.gov. January 4, 2005. Retrieved Oct 22, 2010.
  10. ↑ "Mount Rushmore Park Home". National Park Service. Retrieved April 8, 2012.