The World book encyclopedia : volume 21
World Book, 1984
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The New Encyclopaedia Britannica : volume 21
Encyclopaedia Britannica Inc., 1988
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The New Encyclopaedia Britannica : volume 21
Encyclopaedia Britannica Inc., 2003
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The New book of knowledge : volume 8
Grolier Incorporated, 1997
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The New book of knowledge : volume 9
Grolier Incorporated, 1997
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