Mysteries of the ancient world

Washington, D.C. : National Geographic Society, [1979].
Umfang/Format: 223 p. : col. ill., maps ; 27 cm.

The incredible Incas and their timeless land

von McIntyre, Loren, 1917-
Washington : National Geographic Society, [1975].
Umfang/Format: 199 p. : ill. ; 26 cm.

Discovering man's past in the Americas

von Stuart, George E.
[Washington, D.C. : National Geographic Society, 1969].
Umfang/Format: 211 p. : ill., maps, col. plates. ; 27 cm.