Lignende værker: National Geographic :
- National Geographic : vol. 143, no. 2, February 1973 /
- National Geographic : vol. 143, no. 4, April 1973 /
- National Geographic : vol. 143, no. 5, May 1973 /
- National Geographic : vol. 143, no. 6, June 1973 /
- National Geographic : vol. 143, no. 1, January 1973 /
- National Geographic : vol. 144, no. 3, September 1973 /