Samankaltaisia teoksia: National Geographic :
- National Geographic : vol. 131, no. 2, February 1967 /
- National Geographic : vol. 131, no. 3, March 1967 /
- National Geographic : vol. 131, no. 5, May 1967 /
- National Geographic : vol. 131, no. 6, June 1967 /
- National Geographic : vol. 131, no. 1, January 1967 /
- National Geographic : vol. 132, no. 4, October 1967 /