1.
|
Washington : National Geographic Society, [1975]
|
2.
|
[Washington, D.C.] : The Society, c1982.
|
3.
|
Washington, National Geographic Society [1969]
|
4.
|
Washington : National Geographic Society, c1967.
|
5.
|
[Washington] : The Society, c1975.
|
6.
|
Washington, National Geographic Society [1968]
|
7.
|
Washington : National Geographic Society, c1976.
|
8.
|
[Washington, National Geographic Society, 1974]
|
9.
|
[Washington, D.C.] : National Geographic Society, [1985] ©1985
QL737.P9 R55 1985 |
|
10.
|
Washington, D.C. : The Society, c1986.
|