The Encyclopedia Americana : volume 6
Americana Corporation, 1964
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Collier's encyclopedia : volume 6
Macmillan Educational Company, 1990
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Encyclopedia of knowledge : volume 6
Grolier Incorporated, 1991
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The Encyclopedia Americana : volume 6
Grolier, 1994
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The New Encyclopedia Britannica : volume 6
Encyclopedia Britannica, 1983
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